U.S. military forces carried out four air strikes on Islamic State targets in Syria on Monday and Tuesday and were joined by partner nations in three attacks in Iraq, the U.S. Central Command said.

Fighter, bomber and attack aircraft were used in the raids and all returned safely, the Central Command statement said.

The strikes near Kobani, Syria, destroyed Islamic State fighting positions, a building and an Islamic State unit.

In Iraq, a fighting position southeast of the Mosul Dam and one south of the Bayji oil refinery were destroyed while another strike north of Fallujah suppressed an Islamic State attack, the statement said.

Reuters

(Reuters) - The fiercest fighting in days shook the Syrian border town of Kobani overnight as Islamic State fighters attacked Kurdish defenders with mortars and car bombs, sources in the town and a monitoring group said on Sunday.

Islamic State, which controls much of Syria and Iraq, fired 44 mortars at Kurdish parts of the town on Saturday and some of the shells fell inside nearby Turkey, according to the British-based Syrian Observatory for Human Rights. It said four more mortars were fired on Sunday.

The month-long battle for Kobani has ebbed and flowed. A week ago, Kurds said the town would soon fall. The United States and its coalition partners then stepped up air strikes on Islamic State, which wants to take Kobani in order to strengthen its position in northern Syria.

The coalition has been bombing Islamic State targets in Iraq since August and extended the campaign to Syria in September after Islamic State, a group that espouses a rigid interpretation of Islam and initially fought Syrian President Bashar al-Assad's forces, made huge territorial gains.

Raids on Islamic State around Kobani have been stepped up, with the fate of the town seen as an important test for U.S. President Barack Obama's campaign against the Islamists.

NATO member Turkey, whose forces are ranged along the border overlooking Kobani, is reluctant to intervene. It insists the allies should also confront Assad to end Syria's civil war, which has killed close to 200,000 people since March 2011.

"We had the most intense clashes in days, perhaps a week, last night. (Islamic State) attacked from three different sides including the municipality building and the market place," said Abdulrahman Gok, a journalist in Kobani.

"Clashes did not stop until the morning. We have had an early morning walk inside the city and have seen lots of damaged cars on the streets and unexploded mortar shells," he said.

CAR BOMBS

The Observatory reported two Islamic State car bombs hit Kurdish positions on Saturday evening, leading to casualties. A cloud of black smoke towered over Kobani on Sunday.

A fighter from one of the female units of the main Syrian Kurdish militia in Kobani, YPG, said Kurdish fighters were able to detonate the car bombs before they reached their targets.

"Last night there were clashes all across Kobani ... this morning the clashes are still ongoing," she said, speaking on condition of anonymity.

The Observatory said 70 Islamic State fighters had been killed in the past two days, according to sources at the hospital in the nearby town of Tel Abyab, where Islamic State bodies are taken. Reuters cannot independently confirm the reports due to security restrictions.

The Observatory said some Syrian Arab fighters from the Revolutionaries of Raqqa Brigade, who are fighting alongside Kurdish fighters, had executed two Islamic State captives.

"One was a child of around 15 years old. They shot them in the head," he said.

Islamic State have also used executions throughout their campaigns in Syria and Iraq, killing hundreds of enemy combatants and civilians who oppose their cause, according to Islamic State videos and statements.

Welat Omer, a doctor caring for the few remaining civilians in Kobani, told Reuters by telephone that he was looking after 15 patients, including children and the elderly.

“We need medicine, including antibiotics and milk for the children, and medicine for the elderly, who have heart conditions, diabetes and high blood pressure,” Omer said.

Hundreds of thousands have fled Islamic State's advance. Turkey hosts about 1.5 million Syrian refugees, including almost 200,000 Syrian Kurds from Kobani.

Ankara has refused to rearm beleaguered Kurdish fighters, who complain they are at huge disadvantage in the face of Islamic State's weaponry, much of it seized from the Iraqi military when the militants took the city of Mosul in June.

Turkey views the YPG with suspicion for its long-standing links with the Kurdistan Workers Party (PKK), which has waged a 30-year armed campaign for self-rule in Turkey.

President Tayyip Erdogan was quoted in the Turkish media on Sunday as saying Ankara will never arm the YPG through its political wing, the PYD.

"There has been talk of arming the PYD to establish a front here against Islamic State. For us, the PYD is the same as the PKK, it’s a terrorist organization," he was quoted as saying.

This stance has sparked outrage among Turkey's own Kurds, who make up about 20 percent of the population. Riots in several cities earlier this month killed left than 35 people dead.

(Reuters) - Kurdish forces defending Kobani urged a U.S.-led coalition to escalate air strikes on Islamic State fighters who tightened their grip on the Syrian town at the border with Turkey on Saturday.

A group that monitors the Syrian civil war said the Kurdish forces faced inevitable defeat in Kobani if Turkey did not open its border to let through arms, something Ankara has appeared reluctant to do.

The U.S.-led coalition escalated air strikes on Islamic State in and around Kobani, also known as Ayn al-Arab, some four days ago. The main Kurdish armed group, the YPG, said in a statement the air strikes had inflicted heavy losses on Islamic State, but had been less effective in the last two days.

A Kurdish military official, speaking to Reuters from Kobani, said street fighting was making it harder for the warplanes to target Islamic State positions.

"We have a problem, which is the war between houses," said Esmat Al-Sheikh, head of the Kobani defense council.

"The air strikes are benefiting us, but Islamic State is bringing tanks and artillery from the east. We didn't see them with tanks, but yesterday we saw T-57 tanks," he added.

While Islamic State has been able to reinforce its fighters, the Kurds have not. Islamic State has besieged the town to the east, south and west, meaning the Kurds' only possible supply route is the Turkish border to the north.

The U.N. envoy to Syria on Friday called on Turkey to help prevent a slaughter in Kobani, asking it to let "volunteers" cross the frontier to reinforce Kurdish forces defending the town that lies within sight of Turkish territory.

Turkey has yet to respond to the remarks by Staffan de Mistura, who said he feared a repeat of the 1995 Srebrenica massacre in Bosnia. Kurdish leaders in Syria have asked Ankara to establish a corridor through Turkey to allow aid and military supplies to reach Kobani.

A senior Kurdish militant has threatened Turkey with a new Kurdish revolt if it sticks with its current policy of non-intervention in the battle for Kobani.

Islamic State "is getting supplies and men, while Turkey is preventing Kobani from getting ammunition. Even with the resistance, if things stay like this, the Kurdish forces will be like a car without fuel," said Rami Abdelrahman, who runs the Syrian Observatory for Human Rights, which monitors the conflict in Syria through sources on the ground.

U.S. Defense Secretary Chuck Hagel said on Saturday that retired General John Allen, a U.S. envoy charged with building an international coalition against Islamic State, had just returned to Washington and reported progress.

"There was considerable progress made by General Allen specifically with Turkey," Hagel told a news conference in Santiago. He said U.S. military teams would hold talks in Turkey next week.

"They'll be spending a good deal (of time) next week with Turkey's general staff and appropriate leaders going through the specifics of Turkey's commitments to help the coalition specifically to train and equip areas of their contribution," he added.

PLUMES OF SMOKE

Turkey has been reluctant to help the Kurds defending Kobani, one of three areas of northern Syria where Kurds have established self-rule since the Syrian civil war began in 2011. The main Syrian Kurdish group has close ties to the PKK, which waged a militant campaign for Kurdish rights in Turkey and is listed as a terrorist group by Turkey and its Western allies.

Tall plumes of smoke were seen rising from Kobani on Saturday and the sound of gunfire was close to constant as battles raged into the afternoon, a Reuters journalist observing from the Turkish side of the frontier said.

After sunset, the sounds of gunfire and shelling continued. Red tracer gunfire lit the sky in the eastern sector of the town, much of which has fallen to Islamic State. Battles also raged at the southern and western edges of the town.

A Kurdish military official in the Syrian city of Qamishli, another area under Kurdish control, said thousands of fighters stood ready to go to Kobani were Turkey to open a corridor.

But Ghaliya Naamat, the official, said the fighters in Kobani needed better weaponry. "Medium-range weapons is what is lacking," she told Reuters by telephone.

"According to the news and the information in Kobani, there is no shortage in numbers. The shortage is in ammunition."

If U.S.-led air strikes fail to stop Islamic State militants from overrunning Kobani, it would be a setback for U.S. President Barack Obama's three-week-old air campaign against Islamic State in Syria.

The campaign is part of a U.S. strategy to degrade and destroy the group that has seized large areas of Syria and Iraq, threatening to redraw borders of the Middle East according to its ultra-strict vision of Islam.

U.S. officials have acknowledged that it is possible Islamic State could seize full control of the town in coming days. If that happens, the group could boast that it withstood American air power. The U.S.-led coalition has launched 50 strikes against militant positions around the town.

Hagel, in Santiago as part of a Latin America tour and a summit of Defense Ministers of the Americas in Peru next week, said U.S. air strikes were aimed at driving back Islamic State fighters from Kobani.

"We know ISIL is occupying part of the outskirts of Kobani. It is a dangerous situation and we recognize that," Hagel told the news conference in Santiago.

"We are doing what we can do through our air strikes to help drive back ISIL. In fact there has been some progress made in that area. It is a very difficult problem," he added.

The U.S. military conducted six air strikes against Islamic State militants near Kobani on Friday and Saturday, U.S. Central Command said.

"WE NEED SOMETHING EFFECTIVE"

While much of Kobani's population has fled, 500-700 mostly elderly people remained, with 10,000-13,000 nearby in a border area between Syria and Turkey, U.N. envoy De Mistura said.

The Observatory said no fewer than 226 Kurdish fighters and 298 Islamic State militants had been killed since the group launched its Kobani offensive in mid-September. It said the overall death toll including civilians was probably much higher.

Islamic State views the Kurdish YPG and its supporters as apostates due to their secular ideology.

Idris Nassan, deputy foreign minister of Kobani district, told Reuters by telephone that air strikes had helped Kurdish fighters regain some territory in the south of the city but they were not enough.

"A few days ago, ISIS attacked with a Humvee vehicle, they use mortars, cannons, tanks. We don't need just Kalashnikovs and bullets. We need something effective since they captured many tanks and military vehicles in Iraq," he said, calling for outside powers to send weapons.

"The supply of fighters is very good for YPG," he added. "But fighters coming without arms, without weaponry is not going to make a critical difference."

The Kobani crisis has sparked deadly violence in Turkey. The country's Kurdish population numbers 15 million, and Turkish Kurds have risen up since Tuesday against President Tayyip Erdogan's government, accusing it of allowing their kin to be slaughtered.

At least 33 people have been killed in three days of riots across the mainly Kurdish southeast, including two police officers shot dead in an apparent attempt to assassinate a police chief. The police chief was wounded.

(Reuters) - Islamic State fighters seized more than a third of the Syrian border town of Kobani, a monitoring group said on Thursday, as U.S.-led air strikes failed to halt their advance and Turkish forces looked on without intervening.

With Washington ruling out a ground operation in Syria, Turkey said it was unrealistic to expect it to mount a cross-border operation alone to relieve the mainly Kurdish town.

The U.S. military said Kurdish forces appeared to be holding out in the town, which lies within sight of Turkish territory, following fresh airstrikes in the area against a militant training camp and fighters.

However, the Syrian Observatory for Human Rights said Islamic State, still widely known by its former acronym of ISIS, had pushed forward on Thursday.

"ISIS control more than a third of Kobani - all eastern areas, a small part of the northeast and an area in the southeast," said Rami Abdulrahman, head of the Observatory, which monitors the Syrian civil war.

The commander of Kobani's heavily outgunned Kurdish defenders confirmed that the militants had made major gains, after a three-week battle that has also caused the worst street clashes in years between Turkish police and Kurdish protesters.

Militia chief Esmat al-Sheikh put the area controlled by Islamic State, which controls large amounts of territory in Syria and neighbouring Iraq, at about a quarter of the town. "The clashes are ongoing - street battles," he said by telephone from the town.

Explosions rocked Kobani throughout the day, with black smoke visible from the Turkish border a few kilometres (miles) away. Islamic State hoisted its black flag in the town overnight and a stray projectile landed 3 km (2 miles) inside Turkey.

The town's defenders say the United States is giving only token support with its air strikes, while Turkish tanks sent to the frontier look on but do nothing to defend the town, where the United Nations says only a few hundred remain. Over 180,000 people from the city and surrounding area have fled into Turkey.

U.S. Central Command said it had conducted five strikes near Kobani on Wednesday and Thursday, and that Kurdish forces still appeared to control most of the town.

The strikes damaged an Islamic State training camp and destroyed a support building, as well as hitting one small unit and one large unit of militant fighters, Centcom said.

UNREALISTIC EXPECTATIONS

Turkey's foreign minister, Mevlut Cavusoglu, played down the chances of its forces going to the aid of Kobani.

"It is not realistic to expect Turkey to conduct a ground operation on its own," he told a joint news conference with visiting NATO chief Jens Stoltenberg. However, he added: "We are holding talks ... Once there is a common decision, Turkey will not hold back from playing its part."

Ankara resents suggestions from Washington that it is not pulling its weight, and wants broader joint action that also targets the forces of Syrian President Bashar al-Assad. "We strongly reject allegations of Turkish responsibility for the ISIS advance," said a senior Ankara government source.

"Our allies, especially the U.S. administration, dragged their feet for a very long time before deciding to take action against the catastrophic events happening in Syria," he added.

Turkey has long advocated action against Assad during the civil war, which grew out of a popular uprising in 2011. However, the United States called off air strikes on Damascus government forces at the last minute last year when Assad agreed to give up his chemical weapons. It has also managed so far to fly sorties across Syria with tacit consent from Assad.

Kerry, too, played down Kobani's significance as a pointer to U.S. policy, and said other towns might also be vulnerable to Islamic State as the U.S.-led efforts in the region would take "weeks and months" to play out.

"Kobani is a tragedy because it represents the evil of ISIS, but it is not the definition either of the strategy or the full measure of what is happening with response to ISIS," he told reporters in Boston.

"We are only a few weeks into building the coalition," Kerry said. "The primary goal of this effort has been to provide the space for Iraq to be able to get its government in place and to be begin to push back and to begin to be able to deprive them (Islamic State militants) of their command and control, their supply centres and their training. That is taking place."

Retired U.S. General John Allen, asked by President Barack Obama to oversee the creation and work of the anti-Islamic State coalition, was in Ankara on Thursday for two days of talks with Turkey's leaders.

President Tayyip Erdogan wants the U.S.-led alliance to enforce a "no-fly zone" to prevent Assad's air force flying over Syrian territory near the Turkish border, and to create a safe area for around 1.5 million Syrian refugees in Turkey to return.

Stoltenberg said neither had been discussed by NATO.

TURKISH CLASHES

The anger felt by Turkey's Kurds over Ankara's failure to help their brethren in Syria threatens to unravel a fragile peace process that Erdogan hoped would end a 30-year armed struggle for autonomy by the Kurdistan Workers' Party (PKK).

At least 25 people died in the mainly Kurdish southeast of Turkey on Wednesday during clashes between security forces and Kurds demanding that the government do more to help Kobani.

On Thursday, gunmen wounded a police officer in an attack on a police station in Turkey's southeastern province of Siirt, where five people died during earlier protests. There were also clashes in Istanbul and Ankara.

Wednesday's violence prompted curfews to be imposed in five southeastern provinces, restrictions unseen since the height of the PKK's war against Turkish forces in the 1990s, and streets were calmer as a result.

Erdogan said protesters had exploited the events in Kobani as an excuse to sabotage the peace process.

Selahattin Demirtas, head of the Kurdish People’s Democratic Party (HDP), which had urged Turkish Kurds to take to the streets this week, denied that this had provoked violence. He appealed for calm and said jailed PKK leader Abdullah Ocalan had called for talks with the government to be stepped up.

Kurdish leaders in Syria have asked Ankara, so far in vain, to establish a corridor through Turkey to allow aid and possibly arms and fighters to reach Kobani.

Ankara is suspicious of Syria's Kurds for having achieved self-rule by tacit agreement with Assad after he lost control of the region to anti-government rebels, and fears this could revive secessionist aspirations among its own Kurds.

Turkish police fired tear gas against Kurdish protesters in the town of Suruc near the border overnight, and the shutters of most shops were kept shut in a traditional mark of protest.

Ferdi, a 21-year-old Turkish Kurd watching the smoke rising from Kobani, said if the town fell, the conflict would spread to Turkey. "In fact," he said, "it already has spread here."

(Reuters) - At least 21 people were killed in riots across Turkey, the deadliest street unrest in years, after the Kurdish minority rose up in fury at the government's refusal to protect a besieged Syrian town from Islamic State.

Street battles raged between Kurdish protesters and police across Turkey's mainly Kurdish southeast, in Istanbul and in Ankara, as the fallout from war in Syria and Iraq threatened to unravel the NATO member's own delicate peace process with Kurds.

Across the frontier, U.S.-led air strikes appeared to have pushed Islamic State insurgents back to the edges of the Syrian Kurdish border town of Kobani, which the militants had been poised to capture this week after a three-week siege.

Washington said its war planes, along with those of coalition ally the United Arab Emirates, had struck nine targets in Syria, including six near Kobani that hit Islamic State artillery and armored vehicles. It also struck Islamic State positions in Iraq five times.

Nevertheless, Kobani remained under intense bombardment from Islamic State emplacements, within sight of Turkish tanks that have so far done nothing to help.

U.S. officials were quoted voicing impatience with the Turks for refusing to join the coalition against Islamic State fighters who have seized wide areas of Syria and Iraq. Turkey says it could join but only if Washington agrees to use force against Syrian President Bashar al-Assad as well as the Sunni Muslim jihadists fighting him in a three-year-old civil war.

Turkey's own Kurds, who make up the majority in the southeast of the country, say that President Tayyip Erdogan is stalling while their brethren are killed in Kobani.

Police fired tear gas and water cannon to disperse demonstrators who burned cars and tires. Authorities imposed curfews in at least five provinces, the first time such measures have been used widely since the early 1990s.

Turkish Prime Minister Ahmet Davutoglu told reporters in Ankara that 19 people were killed and 145 wounded in riots across Turkey, vowing that Turkey's own peace process with Kurdish separatists would not be wrecked by "vandalism". Dogan news agency later said the death toll had climbed to 21. At least 10 people died in clashes in Diyarbakir, the largest Kurdish city in Turkey's southeast, according to Agriculture Minister Mehdi Eker, who said an all-day curfew imposed there from Tuesday night would be reviewed on Wednesday.

Pockets of protesters defying the curfew clashed with security forces there later on Wednesday, local media reported.

Others died in clashes between protesters and police in the eastern provinces of Mus, Siirt and Batman. Thirty people were wounded, including eight police officers, in Istanbul.

Disturbances spread to other countries with Kurdish and Turkish populations. Police in Germany said 14 people were hurt in clashes there between Kurds and radical Islamists.

The unrest in Turkey, which has NATO's second largest armed forces, exposes the difficulty Washington has faced in building a coalition to fight Islamic State in Syria and Iraq, two countries with complex, multi-sided civil wars in which every country in the region has a stake.

BLACK FLAG

Islamic State fighters besieging Kobani hoisted their black flag on the eastern edge of the town on Monday. Since then, U.S.-led air strikes have been redoubled, and the town's defenders say the insurgents have been pushed back.

Intense gunfire and loud explosions could be heard on Wednesday morning from across the Turkish frontier, and huge plumes of gray smoke and dust rose above the town, where the United Nations says only a few hundred inhabitants remain.

"They are now outside the entrances of the city of Kobani. The shelling and bombardment was very effective and as a result of it, IS (Islamic State) have been pushed from many positions," Idris Nassan, deputy foreign minister of the Kurdish-run Kobani district administration, told Reuters by phone.

"This is their biggest retreat since their entry into the city and we can consider this as the beginning of the countdown of their retreat from the area."

U.S. officials, acknowledging it will be difficult to shield Kobani from the air, have played down its strategic importance.

"People need to understand we need a little strategic patience here. This group is not going to go away tomorrow, and Kobani may fall. We can't predict whether it will or it won't," Pentagon spokesman Rear Admiral John Kirby said on CNN.

"There will be other towns that they will threaten, and there will be other towns that they will take. It is going to take a little bit of time."

Secretary of State John Kerry said: "As horrific as it is to watch in real time what is happening in Kobani ..., you have to step back and understand the strategic objective."

Islamic State has been advancing on the town from three sides and pounding it with artillery despite dogged resistance from heavily outgunned Kurdish forces.

Kurdish media said Kurdish fighters thwarted a car bomb on positions in Kobani, saying the vehicle blew up before reaching its target. An Islamic State source on Twitter said the attack destroyed a police station. Neither account could be verified but a huge explosion could be seen from across the border.

In Turkey, parliament voted last week to authorize cross-border intervention, but Erdogan and his government have so far held back, saying they will join military action only as part of an alliance that also confronts Assad.

Erdogan wants the alliance to enforce a "no-fly zone" to prevent Assad's air force flying over Syrian territory near the Turkish border and create a safe area for an estimated 1.2 million Syrian refugees in Turkey to return.

France said it supported the idea of a safe area, and Britain said it was studying it. But it is clear the proposal has not taken hold in Washington, which has been bombing Islamic State targets in Syria without Assad raising objections, and does not want to be dragged into a conflict against Damascus.

"At the moment, the American air force is flying all over Syria with the permission of the Assad government," said Tim Ripley, a defense expert for Jane's Defence Weekly.

"To try and impose a no-fly zone would potentially involve a major air war against one of the biggest air forces in the Middle East ... which would only be a distraction from the fight against (Islamic State)," he said.

Kerry, repeating lukewarm views of other U.S. officials, said: "The buffer zone is an idea that has been out there. It is worth examining, it's worth looking at very, very closely." Pentagon spokesman Kirby said: "It is now not on the table as a military option that we are considering."

U.S. IMPATIENCE

The conflict has already opened up a fissure in relations between the United States and Turkey, its most powerful ally in the area. U.S. Vice President Joe Biden was forced to apologize last week after Erdogan took umbrage at comments Biden made at Harvard University, in which he blamed Turkey's open borders for allowing Islamic State to bring in recruits.

An unnamed senior U.S. official told the New York Times on Tuesday there was "growing angst about Turkey dragging its feet to act to prevent a massacre less than a mile from its border".

"This isn’t how a NATO ally acts while hell is unfolding a stone's throw from their border," the official said.

Kerry said Turkey was still deciding what role it would play. Retired U.S. General John Allen, charged with building a coalition against Islamic State after it seized about a third of neighboring Iraq, is due in Turkey this week.

But, while taking in Kobani's refugees and treating its wounded, Turkey has deep reservations about deploying its own army in Syria. Beyond becoming a target for Islamic State, it fears being sucked into Syria's three-year-old civil war.

It also distrusts Syria's Kurds, allies of Turkey's own Kurdistan Workers' Party (PKK), which waged a decades-long insurgency for Kurdish autonomy in which around 40,000 people were killed.

The PKK's jailed leader, Abdullah Ocalan, has said any massacre of Kurds in Kobani would doom a fragile peace process with the Turkish authorities, one of the most important initiatives of Erdogan's decade in power.

The street protests across Turkey were already making the prospect of reconciliation with nationalists seem more remote, as protesters set fire to Turkish flags and attacked statues of the founder of modern Turkey, Mustafa Kemal Ataturk.

Selahattin Demirtas, co-chair of the HDP, Turkey's leading Kurdish party, condemned such acts as "provocations carried out to prevent help coming to the east (Kobani) from the west".

(Reuters) - The main Kurdish armed group in Syria called on its kinsmen across the region to help it stop a massacre in the Syrian town of Kobani as Islamic State militants armed with tanks edged closer on its outskirts and pummelled it with artillery fire.

Islamic State's battlefield gains in recent months have come as Syrian President Bashar al-Assad's forces have focussed on other rebel groups. On Friday the army advanced on the city of Aleppo further west, threatening rebel supply lines in a potentially major reversal.

U.S.-led forces have been bombing Islamic State targets in Syria and Iraq but the action has done little to stop the group's advance in northern Syria towards the Turkish border, piling pressure on Ankara to intervene.

Canada said it would send fighter jets and other aircraft to take part in the U.S.-led strikes on Islamic State in Iraq for a period of up to six months.

Turkey said it would do what it could to prevent Kobani, a predominantly Kurdish town just over its southern border, from falling into Islamic State. It has stopped short of committing to any direct military intervention and Syria warned on Friday against any Turkish "aggression" on its territory.

A statement issued by the YPG, the main Kurdish armed group, vowed "never ending" resistance to Islamic State in its advance on Kobani. "Every street and house will be a grave for them."

"Our call to all the young men and women of Kurdistan ... is to come to be part of this resistance."

DESTRUCTION

Esmat al-Sheikh, head of the Kurdish forces defending Kobani, said the distance between his fighters and the insurgents was now less than one kilometre (half a mile).

"We are in a small, besieged area. No reinforcements reached us and the borders are closed," he told Reuters by phone. "My expectation is for general killing, massacres and destruction."

Islamic State has carved out swathes of eastern Syria and western Iraq in a drive to create a caliphate between the Euphrates and the Tigris rivers. Kobani's resistance has prevented it from consolidating territory across Syria's north.

Fighting continued after the sun set, with artillery strikes on residential areas east and southwest of Kobani's centre. Kurds returned fire, and red tracer bullets targeting Islamic State strongholds east of the city flew over rooftops, a Reuters correspondent on the Turkish side of the border said.

Remzi Savas, 53, smoked a cigarette and listened to the gunfire over the border.

"My son is over there, he crossed through a minefield to get there. He is just 14. There are many children fighting for the YPG, we can't hold them back. They think they'll lose everything if Kobani falls."

The British-based Syrian Observatory for Human Rights said at least 80 shells had hit the town, known as Ayn al-Arab in Arabic, and there were heavy clashes in the east and southeast.

The fighting has driven Kurds from across northern Syria from their homes across the border into Turkey.

"It's a dramatic humanitarian tragedy as we have all witnessed," U.N. High Commissioner for Refugees Antonio Guterres said in Geneva. "It's the largest single outflow of Syrians in a few days, 160,000 people."

ALEPPO ENCIRCLED

Further west, a Syrian army advance threatened to take the last main rebel supply route leading into Aleppo from the north and reverse two years of gains by Assad's foes.

"They are going to encircle Aleppo," said Abu Abdo Salabman, a member of the political office of the Mujahideen Army, a rebel group viewed as part of the moderate opposition to Assad.

"They are bombing us non-stop," said Salabman, who was not using his real name. "They are marching on us and the regime air force is non-stop."

The Syrian army has taken control of three villages, state television said, in a campaign by Assad's forces that could encircle insurgents in the city.

Although there are smaller, more indirect routes into Aleppo, taking the northern road would also allow the army to besiege areas of the city which fell to insurgents in 2011, a tactic it used to retake Homs city in May.

Assad's forces are fighting a mixture of rebel groups in Syria, including Islamic State but also a mix of western-backed forces in a conflict which has killed nearly 200,000 people.

This year, Washington and its allies have shifted focus in Syria from battling Assad to combating Islamic State.

The U.S. military said coalition forces carried out strikes in Iraq and Syria overnight on Thursday. In Syria they destroyed an Islamic State garrison, two of the militant group's tanks and hit two mobile oil refineries and a training camp.

In Iraq, government forces recaptured the town of Dhuluiya, about 70 km (45 miles) north of Baghdad, which had been under siege by Islamic State.

Prime Minister Haider al-Abadi called on Iraq's bickering political factions to unite. In a message to mark the Muslim holy feast of Eid, he said the battle against Islamic State would continue to the end.

TURKISH DILEMMA

Village by village, Kurdish forces in northern Iraq have regained around half the territory they gave up in August when Islamic State militants tore through their defences in the northwest, prompting the United States to launch air strikes in September, its first since 2011.

Turkey, however, insists the air strikes alone will not contain the Islamic State threat, and wants simultaneous action to be taken against Assad's government, including the creation of a no-fly zone on the Syrian side of the border.

Prime Minister Ahmet Davutoglu said Turkey would do what it could to prevent Kobani from falling to the militants but stopped short of committing to the sort of intervention Kurds have called for.

"We wouldn't want Kobani to fall. We'll do whatever we can to prevent this from happening," Davutoglu said in a discussion with journalists broadcast on the A Haber television station.

Parliament gave the government powers on Thursday to order cross-border military incursions against Islamic State, and to allow forces of the U.S.-led foreign coalition to launch similar operations from Turkish territory.

Syria said Turkey's decision was an act of aggression which could have "catastrophic consequences".

But Davutoglu appeared to pull back from any suggestion that Turkey was planning a military incursion, saying this could drag Ankara into a wider conflict along its 900 km (560-mile) border.

Ankara fears intervention could worsen security on its border by strengthening Assad and bolstering Kurdish fighters linked to the Kurdistan Workers Party (PKK), which has waged a three-decade insurgency against the Turkish state.

(Reuters) - A Twitter account run by an Qaeda member said the leader of the al Qaeda-linked Khorasan group was killed in a U.S. air strike in Syria, SITE monitoring service said on Sunday, following several days of uncertainty over whether he survived the raid.

A U.S. official on Sept. 24 said the United States believed Mohsin al-Fadhli, a senior al Qaeda operative, had been killed in a strike a day earlier, but the Pentagon said several hours later that it was still investigating what had happened to him.

In a message posted on Sept. 27, the jihadist offered condolences for the death of Kuwaiti-born Fadhli, otherwise known as Abu Asmaa al-Kuwati or Abu Asmaa al-Jazrawi, following the Sept. 23 air strike, SITE reported.

U.S. officials have described Khorasan as a network of seasoned al Qaeda fighters with battlefield experience mostly in Pakistan and Afghanistan that is now working in league with al Qaeda’s Syrian affiliate, the Nusra Front.

Khorasan is a term for an area including parts of Pakistan and Afghanistan where al Qaeda’s main council is believed to be in hiding.

After the Sept. 23 strikes, U.S. officials said they were was still assessing how badly Khorasan had been hit. Islamist militants on social media have said there were unconfirmed reports that the 33-year-old Fadhli had been killed.

SITE did not name the jihadist who reported Fadhli's death but said he had trained under a close associate of al Qaeda leader Ayman al-Zawahri and had fought in Khorasan before traveling to Syria.

A 2012 State Department notice offering a $7 million reward for information on Fadhli's whereabouts said he was an al Qaeda financier close to al Qaeda founder Osama bin Laden and among the few who knew in advance about the Sept. 11, 2001, attacks.