U.N. investigators said on Wednesday that they had documented three further uses of banned chlorine weapons by Syrian government forces that constituted war crimes, and urged major powers to help avert a "massacre" in the final battle for Idlib.
The attacks caused injuries in the Damascus suburb of Douma and in Idlib in the northwest in January and early February, they said in their latest report.
They said they were still investigating a suspected chemical attack in Douma on April 7 that killed at least 49 people and wounded up to 650.