UN inquiry to blame Syrian military for chlorine gas attacks: Source

An international inquiry will identify two Syrian air force helicopter squadrons and two other military units responsible for chlorine gas attacks on civilians, a Western diplomat told Reuters on Friday.

The finding, set to be published next week by the United Nations and the OPCW, the global chemical weapons watchdog, is based on Western and regional intelligence, the diplomat said.

"It was the 22nd Division, the 63rd Brigade and the 255 and 253 squadrons of the Syrian government," the envoy said.

The identification of specific military units responsible for attacks could strengthen a push by some Western members of the UN Security Council for a robust response, focused on sanctions and accountability.

President Bashar al-Assad's government has denied using gas on the battlefield, and said it will cooperate with the Organisation for the Prohibition of Chemical Weapons over accusations that the government has used poison gas against insurgent-held areas during Syria's civil war.

Responding to the new finding, a Syrian military source told Reuters: "The Syrian state... and we, the Syrian Arab army, have said more than once that the army has not and will not use any banned weapon, especially chemical or poison weapons.

"This issue is completely void of truth. We consider the United Nations to be a tool in the hands of some countries which support terrorists," the source said, adding that the UN had not responded to Syrian requests to investigate alleged use of chemical weapons by insurgents.

The year-long joint UN and OPCW inquiry, which is investigating reports of attacks between 11 April 2014 and 21 August 2015, is due to submit its fourth report to the UN Security Council next week. The third report, in August, blamed Syrian government troops for two chlorine gas attacks and Islamic State militants for using sulphur mustard gas.

It is unclear whether the fourth report will assign blame to individuals. The inquiry has focused on nine attacks in seven areas of Syria, where a separate OPCW fact-finding investigation concluded that it was likely chemical weapons have been used.

Eight of the attacks investigated involved the suspected use of chlorine. The inquiry said it had not yet been able to reach conclusions in six cases, though it said three of those cases warranted further investigation.

"At least two others were chlorine and were carried out at the hands of the Syrian air force," the diplomat said. "There is no indication that any opposition groups used chlorine."

In 2013, Syria agreed to destroy 1,300 tonnes of declared chemical weapons under a deal brokered by Moscow, Damascus's main international backer, and Washington, which supports the Syrian opposition.

In a separate confidential report seen by Reuters, OPCW inspectors concluded in July, after 16 visits to Damascus since April 2014, that Syria had failed to explain "scientifically or technically" the discovery of banned agents by its inspectors since that date, including sarin and VX nerve agents.

Chlorine is a "dual use" substance widely used in industry, meaning Syria was allowed to keep its stocks. However, its use on the battlefield is banned under the 1997 Chemical Weapons Convention, which Syria joined in 2013.

The latest suspected use of chlorine gas was last week, when rescue workers and a monitoring group reported dozens of cases of suffocation in an opposition neighbourhood in the city of Aleppo.

Possible showdown

If inhaled, chlorine gas turns to hydrochloric acid in the lungs and can kill by burning the lungs and drowning victims in the resulting body fluids.

The new finding, which blames specific military units, could set the stage for a showdown at the Security Council, pitting the US, Britain and France against Russia and China.

Beijing and Moscow have veto powers as permanent Security Council members and have protected Syria's government from action by blocking several resolutions, including an attempt to refer the situation in Syria to the International Criminal Court.

Syria is not a member of the ICC, so any war crimes cases against suspects must be referred by the Security Council to the court in The Hague.

Some Western diplomats worry that the Security Council could respond weakly to the reported chemical weapons attacks or that the issue could be sidelined because of the fragility of a Syria ceasefire deal agreed by Moscow and Washington.

"We don't want the [UN/OPCW] report to be taken hostage by the political process in Syria," said a senior Security Council diplomat, speaking on condition of anonymity.

A second senior Security Council diplomat said: "Normally on Syria policy, when we go down this US-Russia track, either nothing happens because they can't agree... or if something does come out it tends to be Russian-flavoured."

"Neither of those outcomes is good," the envoy said.

Some diplomats said UN/OPCW investigators may ask for more time to finish their fourth report, in which case the Security Council may renew the mandate for the inquiry for a short time.

Samantha Power, the US ambassador to the UN, said on Thursday it was important those compiling the inquiry "go as far as they can" to identify individuals and entities involved in the attacks. The United States planned "to push to extract from the council as much as we can" on a response, she said.

"We're in very close contact with other council members about what that might look like," Power said. "We also retain the ability to take what's in the report and act nationally and multilaterally in order to ensure real consequences for those actors who are named."

US President Barack Obama initially said the use of chemical weapons in Syria would cross a "red line," but he failed to follow through with threatened air strikes after a sarin gas attack in August 2013 killed as many as 1,400 in the Ghouta neighbourhood of Damascus.

French Foreign Minister Jean-Marc Ayrault said on Tuesday he would fight vigorously for sanctions on those responsible for the gas attacks being investigated. A French diplomat, speaking on condition of anonymity, said Paris had been working on "the contours of what a satisfying resolution would look like for us".

"The American position is not as firm on this issue as ours," the French diplomat said. "What's at stake goes well beyond the Syrian conflict. It's about not making the use of chemical weapons a banality."