Watchdog to report soon on whether chemical weapons were used in larger-scale attack in Douma

An investigation by the chemical weapons watchdog has found that chlorine is likely to have been used in an attack on a Syrian town in February.

In what is likely to be seen as a dry run for a more controversial report later this month, the Organisation for the Prohibition of Chemical Weapons found that the February attack on the neighbourhood of Saraqeb was caused by the dropping of two cylinders that had contained chlorine on to a field in the town.

Chemical weapons watchdog amends claim over Salisbury novichok Read more

The OPCW is to report soon on whether chemical weapons were used on a larger-scale attack in Douma, eastern Ghouta, in May. Aspects of the evidence gathered at Saraqeb and Douma are very similar, weapons experts said.

The OPCW does not have the power to attribute responsibility for attacks, and the UN body that did have the power to attribute blame has been closed after Russia used its veto to block the renewal of its mandate.

Russia will not allow the mandate to be renewed unless the UN security council – on which Russia has a veto – is empowered to reject or endorse the body’s findings. Moscow has also become increasingly critical of the OPCW’s neutrality and working methods, especially after its experts found that a military-grade nerve agent had been deployed in the Salisbury attack on Russian former double-agent Sergei Skripal.

The fact-finding mission by the OPCW on the Saraqeb attack determined that “chlorine was released from cylinders by mechanical impact on 4 February,” it said on Wednesday. The team’s conclusions were based on finding two cylinders that were determined as previously containing chlorine.

In addition, the OPCW said environmental samples had demonstrated the unusual presence of chlorine in the local environment. Its team had also interviewed witnesses, and found that a number of patients at medical facilities shortly after the incident showed signs and symptoms consistent with exposure to chlorine.

The incident is by no means the worst chemical weapons attack during the seven-year civil war, but it led to 11 people being treated for breathing difficulties. Western observers said the use of helicopters in the attack suggested Syrian government involvement since the opposition did not have access to helicopters.

The Syrian government produced a three-page denial of responsibility, and failed to answer a further set of OPCW questions sent on 14 March.

In a brief statement Ahmet Üzümcü, the head of OPCW, said: “I strongly condemn the use of toxic chemicals as weapons by anyone, for any reason, and in any circumstances. Such acts contradict the unequivocal prohibition against chemical weapons.”

Medics have claimed the Douma attack on 7 April led to 40 deaths. The scale of the attack prompted the UK, France and the US to mount cruise missile strikes on what it said were Syrian government chemical weapons sites.

Following delays, the OPCW was allowed to access the Douma site where it gathered more than 100 environmental samples.

Last month, Russia held a press conference close to the OPCW headquarters in The Hague, at which it produced witnesses that claimed no chemical weapons attack had occurred, and that any choking had been due to dust inhalation. Russia said the whole attack was faked on video footage by UK intelligence-funded Syrians.

The UN secretary general, António Guterres, has been working privately to bridge the differences between Russia and the west on how to reform the OPCW so that it has powers to attribute responsibility. The French government is due to hold a ministerial-level conference in Paris on Friday to build an alliance of countries determined to reconstruct an accountability mechanism for chemical weapons use, if necessary outside the confines of the UN.