A toxic chemical, almost certainly chlorine, was used “systematically and repeatedly” as a weapon in attacks on villages in northern Syria earlier this year, the global chemical weapons watchdog said Wednesday.

The Organization for the Prohibition of Chemical Weapons said that a report by a fact-finding mission it sent to Syria based its conclusion on dozens of interviews with victims, physicians, eye-witnesses and others.

The report, which was not immediately published in full, does not apportion blame for the chlorine attacks on three villages in northern Syria, OPCW spokesman Michael Luhan said. The OPCW put out only a short statement summarizing the findings.

An earlier report by the mission also said chlorine likely was used as a weapon in Syria.

Human Rights Watch said in May that it had strong evidence that in April this year Syrian army helicopters dropped bombs containing chlorine on the same rebel-held villages mentioned by the OPCW report.

Chlorine is a toxic industrial gas that is not specifically classified as a chemical weapon.

The attacks earlier this year came as Damascus and the OPCW were involved in a complex mission to remove Syria’s stockpile of chemical weapons and precursor chemicals from the country. All of the poison gas, nerve agents and other chemicals declared by Syria have now been removed from the country and the most toxic parts of the arsenal destroyed.

The OPCW said the fact finding mission would continue its work as there was “a spate of new allegations” of chlorine attacks in Syria in August.

(AP)