THE HAGUE, Netherlands (AP) - An investigation by the global chemical weapons watchdog has found "reasonable grounds to believe" that a blistering agent was used during the shelling of a Syrian town in 2015, the organization said Wednesday.
The report by the Fact-Finding Mission of the Organization for the Prohibition of Chemical Weapons said the chemical was likely used as a weapon on Sept. 1, 2015, in Marea, between the northwestern city of Aleppo and the Turkish border.
It said a probe into another incident two days later did not find sufficient evidence to conclusively establish if chemical weapons were used.
A 2015 report by the same mission said that sulfur mustard was very likely used in Marea days earlier. A U.S. diplomat said that at the time the town was the scene of fighting between Syrian opposition forces and the Islamic State group.
The Fact-Finding Mission is not mandated to apportion blame for the use of chemicals as weapons. Earlier investigations by the mission have established that chlorine, sulfur mustard, and sarin have been used as chemical weapons during the grinding conflict in Syria.
A separate investigative panel set up by the watchdog has twice said it found "reasonable grounds to believe" that Syrian government forces used chemical weapons. Damascus denies using such weapons.
Syria joined the Hague-based OPCW in 2013 under intense pressure from the West after a deadly poison gas attack on a Damascus suburb. As part of the process of joining, it submitted a list of chemical weapons and precursor chemicals that were quickly removed from the country and destroyed under international supervision. However, unanswered questions remain about whether the Syrian government declared all of its stockpiles.
The latest fact-finding mission report was passed on to the OPCW member states and the United Nations Security Council.