OPCW attributes sixth chemical weapons attack to Syrian Arab Armed Forces in new report

The Secretariat of the Organisation for the Prohibition of Chemical Weapons (OPCW)’s fifth report, released on 21 January 2026, has concluded there are reasonable grounds to believe that the Syrian Arab Air Forces were the perpetrators of the chemical weapons attack on 1 October 2016 in Kafr Zeita in Syria. It is the sixth chemical weapons attack to have been attributed to the Syrian Arab Armed Forces by the OPCW.

The comprehensive investigation was conducted from March 2024 to December 2025 by the Investigation and Identification Team (IIT), a fact finding team mandated to identify the perpetrators of specific instances of chemical weapons use in Syria but without prosecutorial or judicial power.

"Based on the analysis and corroboration of all obtained information," the OPCW wrote, "the Secretariat concludes there are reasonable grounds to believe the Syrian Arab Air Force dropped at least one yellow pressurised cylinder, which hit a cave system in the Wadi al-Aanz valley in Kafr Zeita."

"The pressurised cylinder impacted two ventilation openings near the Al Maghara Hospital. The cylinder then tumbled down and came to rest near the entrance of the cave system. Upon impact, the cylinder ruptured and pressurised released chlorine gas, dispersing through the Wadi al-Aanz valley, injuring 35 named individuals and affecting dozens more."

"The Secretariat reached its conclusions on the basis of the 'reasonable grounds' standard of proof, as consistently applied by international fact-finding bodies and commissions of inquiry. The assessment included information from the Fact-Finding Mission, States Parties, interviews conducted by the IIT, and analyses of samples, computer modelling, satellite imagery, front-line maps, authenticated videos and photos, and other relevant data. This information was considered holistically and OPCW procedures were strictly adhered to. The Secretariat also thoroughly considered the positions put forward by the former Syrian authorities but was unable to obtain any concrete information supporting those positions. To date, five reports identifying perpetrators have been issued by the OPCW on seven cases of use of toxic chemicals as weapons in Syria."

"Systematic use of toxic chemicals as weapons"

OPCW Director-General Ambassador Fernando Arias said: "We welcome the assistance received from the new Syrian authorities, marking the first cooperation by the Syrian Arab Republic with an IIT investigation. These actions are in line with the commitments made by President Ahmad al-Sharaa, when I visited Damascus in February last year. This represents a significant milestone and a meaningful contribution to international accountability."

"This new report provides further evidence of a pattern of systematic use of toxic chemicals as weapons by the former Syrian authorities against their own people. The report and its findings are now in the hands of the international community, the United Nations, and the States Parties to the Chemical Weapons Convention. The Secretariat will continue its investigations to identify perpetrators of chemical weapons use in Syria through its Office of Special Missions," he added.

The IIT has previously attributed five other incidents of chemical weapons use in Syria to the Syrian Arab Air Forces, including three cases in Ltamenah in March 2017, one case in Saraqib in February 2018 and one case in Douma in April 2018.

The IIT's fourth report, released on 22 February 2024, attributed a chemical attack in Marea, Syria, to units of the Islamic State in Iraq and the Levant, commonly abbreviated to ISIL.