US fears Syrian chemical weapons may fall into IS hands

The United States expressed concern Thursday that undeclared Syrian chemical weapons could fall into the hands of Islamic State (IS) militants.

US Ambassador Samantha Power raised the concerns as a joint UN and Organization for the Prohibition of Chemical Weapons mission winds up a drive to eliminate Syria's chemical arsenal.

The mission is supposed to formally conclude its work by September 30, but its chief Sigrid Kaag said there were still "discrepancies and questions" related to Syria's weapons declarations.

"The international community must continue to press for a resolution of all discrepancies and omissions," said Power.

"The US is concerned about all discrepancies and also the potential that there are real omissions in the declaration," she added.

Power said the Security Council, currently presided by the United States, "intends to stay very much on top of this."

"Extremist groups have terrorized everyone they come into contact with in Syria and Iraq and these weapons stocks, if there are any left, could fall into their hands," she said.

The United States has launched an air campaign against IS as they have swept through large parts of Iraq from strongholds in Syria.

Power also recalled that the Syrian government had carried out chemical weapons attacks itself, particularly on August 21 2013 in a Damascus suburb.

Kaag, delivering her last report to the Security Council as the mission's chief, said Damascus had presented "four amendments" to its weapons declaration, and that there had been "constructive" discussions on certain discrepancies, including the volume of toxic chemicals declared.

A total of 1,300 tonnes of chemical agents have been removed from Syria and subsequently destroyed at sea.

'A dozen' Americans fighting with IS

The United States believes about "a dozen" Americans are fighting with IS in Iraq and Syria, a Pentagon spokesman said Thursday.

There are about 100 US nationals "operating inside of Syria" but it was unclear which rebel groups they were associated with, spokesman Colonel Steven Warren said.

"We believe there are maybe a dozen that are with ISIL (IS militants)," he said.

Senior US officials have voiced concern at the presence of foreign fighters among the militants who hold Western passports, potentially enabling them to return from the battlefield prepared to carry out terror attacks in Europe or the United States.

US intelligence officers have estimated that there are roughly 1,000 European volunteers among rebel forces in Syria, but it remains unclear how many were linked to the IS.

At least one American fighting for IS was killed in combat in Syria, officials say, while authorities were investigating if a second US national also died as an IS recruit.

The Federal Bureau of Investigation has arrested several people trying to travel from the United States to Syria to support the IS militants, Matthew Olsen, director of the US National Counter-Terrorism Center, said Wednesday.

IS militants have seized large swathes of territory in Iraq in recent months, displaying brutal tactics and executing two American reporters.

Syrian raid kills 18 IS militants

The death toll from a Syrian government raid on an IS stronghold in eastern Syria has risen to 18, a monitor said Thursday.

The Syrian Observatory for Human Rights said Wednesday's strike destroyed a building being used as a headquarters and a prison by IS militants in Deir Ezzor province.

The strike on the village of Ghareebeh killed "at least 18 jihadist fighters and leaders, most of them non-Syrians and including an American," the Britain-based Observatory said.

On Wednesday, the Observatory reported that at least five IS militants had been killed in that attack, and that the raid enabled some of the jail's prisoners to escape.

IS militants control most of the oil-rich province of Deir Ezzor since routing government troops in July.

Iraq strikes kill IS chief's aide

Air strikes in northern Iraq on Thursday killed the top aide of IS chief Abu Bakr al-Baghdadi, the country's ranking army officer said.

"Iraqi warplanes carried out a security operation today, resulting in the killing of... Abu Hajr al-Suri," General Babaker Zebari told AFP.

Zebari said the strikes in Nineveh province were "based on accurate intelligence information," and that the target was destroyed.

It was not possible to independently confirm Suri's death.

The area where the strikes were carried out, located between Mosul and Tal Afar, is outside government control, posing a major challenge to verifying Suri's death.

IS-led militants launched a major offensive in June, overrunning Iraq's second city Mosul and then sweeping through much of the country's Sunni Arab heartland.

IS launched a renewed push in Iraq last month that drove Kurdish forces back toward the capital of their autonomous northern region, sparking a campaign of US air strikes that have helped them regain some ground.

The federal government won its first major military success of the conflict on Sunday, when Iraqi forces, Shiite militiamen and Kurdish fighters broke a months-long siege of the town of Amerli and surrounding areas.

Turkey arrests 19 militants in border province

Turkey has arrested 19 militants affiliated with the IS in its southern province of Gaziantep bordering Syria, its governor said on Thursday.

"The trial of 19 suspects caught so far has been continuing and they are under arrest," Gaziantep province governor Erdal Ata was quoted as saying by the private Dogan news agency.

The governor also said police had caught suspected IS-linked militants coming from Europe or Caucasus, carrying backpacks, at the Gaziantep airport or at the border.

Ata said those believed to have committed crimes would be put on trial while suspected IS sympathisers would be deported.

IS militants are still holding 49 Turks hostage, including diplomats and children, abducted from the Turkish consulate in Mosul in Iraq on June 11.