THE HAGUE: Former Syrian president Bashar Assad’s forces deployed chlorine gas in a 2016 attack that injured at least 35 people, the world’s chemical weapons watchdog concluded Thursday.

The October 2016 attack near a field hospital outside the town of Kafr Zeita, in western Syria, was already well-documented but the Organization for the Prohibition of Chemical Weapons (OPCW) for the first time accused Assad’s forces.

“There are reasonable grounds to believe that one Mi8/17 helicopter of the Syrian Arab Air Force dropped at least one yellow pressurised cylinder,” the OPCW said in a report.

“Upon impact, the cylinder ruptured and released chlorine gas, which dispersed through the Wadi Al-Aanz valley, injuring 35 named individuals and affecting dozens more,” OPCW investigators concluded.

The team interviewed dozens of witnesses, analyzed samples and reviewed satellite images.