An investigation by the international chemical weapons watchdog confirmed Friday that sarin nerve agent was used in a deadly April 4 attack on a Syrian town, the latest confirmation of chemical weapons use in Syria’s civil war.

The attack on Khan Sheikhoun in Syria’s Idlib province left more than 90 people dead and sparked outrage around the world as photos and video of the aftermath, including quivering children dying on camera, were widely broadcast.

“I strongly condemn this atrocity, which wholly contradicts the norms enshrined in the Chemical Weapons Convention,” Organization for the Prohibition of Chemical Weapons director-general Ahmet Uzumcu said in a statement. “The perpetrators of this horrific attack must be held accountable for their crimes.”

But the investigation’s mandate did not include identifying who carried out the attack. Its findings will be used by a joint United Nations-OPCW investigation team to assess who was responsible.

The OPCW scheduled a meeting of its executive council for July 5 to discuss the findings.

The U.S. State Department said in a statement issued Thursday night after the report was circulated to OPCW member states that “The facts reflect a despicable and highly dangerous record of chemical weapons use by the Assad regime.”

President Donald Trump cited images of the aftermath of the Khan Sheikhoun attack when he launched a punitive strike days later, firing cruise missiles on a Syrian government-controlled airbase from where U.S. officials said the Syrian military had launched the chemical attack.


The OPCW report doesn’t assign blame. The findings of the report, however, will be used in an investigation to try to assess who was responsible for using the deadly nerve agent. (Ammar Abdullah/Reuters)

It was the first direct American assault on the Syrian government and Trump’s most dramatic military order since becoming president months before.

British Foreign Secretary Boris Johnson is urging the international community to work together to bring to justice those responsible for the attack.

“This confirmation cannot be ignored,” Johnson says, adding that “the U.K.’s own assessment is that the Assad regime almost certainly carried out this abominable attack.”

“I urge our international partners to unite behind the need to hold those responsible for this atrocity to account.”

While the OPCW report confirms a White House claim that the sarin release likely originated from a crater in a road, the investigators say they were, “unable to retrieve any items from the site which would indicate the means of dispersal of a chemical.”  

“After analyzing photographs and video supplied by witnesses, the FFM could not establish with a great degree of confidence the means of deployment and dispersal of the chemical,” the report says.


A combination image released by the U.S. Department of Defense which they say shows the impact crater associated with the April 4 attack, released after U.S. cruise missile strike against Syria on April 7. (U.S. DoD/Reuters)

Syrian President Bashar al-Assad has denied using chemical weapons. His staunch ally, Russian President Vladimir Putin, said earlier this month that he believed the attack was “a provocation” staged “by people who wanted to blame him [Assad] for that.”

Russian Foreign Minister Sergey Lavrov said the report, which was not released in full, doesn’t back claims by the U.S. and its allies that the sarin was dropped from aircraft.

The report “said they were not sure that the sarin found there had been air-dropped in bombs,” Lavrov said in Moscow. “They don’t know how the sarin ended up there, yet tensions have been escalating for all these months.”

On June 25, the German newspaper Welt published an article by American investigative journalist Seymour Hersh, who wrote that before ordering the missile attack, Trump was “warned by the U.S. intelligence community that it had found no evidence that the Syrians had used a chemical weapon.”

Analyzed samples 

Both the U.S. and the OPCW were at pains to defend the probe’s methodology. Investigators did not visit the scene of the attack, deeming it too dangerous, but analyzed samples from victims and survivors as well as interviewing witnesses.

“A rigorous methodology was employed for conducting an investigation of alleged use of chemical weapons that took into account corroboration between interviewee testimonies; open-source research, documents, and other records; and the characteristics of the samples including those provided by the government of the Syrian Arab Republic,” the OPCW said in a statement.

The Syrian government acceded to the Chemical Weapons Convention, which is enforced by OPCW, in 2013 after it was blamed for a deadly poison gas attack in a Damascus suburb. As it joined, Assad’s government declared some 1,300 tonnes of chemical weapons and precursor chemicals which were subsequently destroyed in an unprecedented international operation.

However, the organization still has unanswered questions about the completeness of Syria’s initial declaration, meaning that it has never conclusively been able to confirm that the country has no more chemical weapons.