The New York Times reports: Syrian military helicopters dropped bombs containing chlorine on civilians in at least two attacks over the past two years, a special joint investigation of the United Nations and an international chemical weapons monitor said on Wednesday in a confidential report.

The report also found that militants of the Islamic State in Syria had been responsible for an attack last year using poisonous sulfur mustard, which, like chlorine, is banned as a weapon under an international treaty.

The 95-page report, based on a yearlong investigation, represents the first time the United Nations has blamed specific antagonists in the Syrian conflict for the use of chemical weapons, which is a war crime. Previous inquiries have determined that chemical weapons were used, but did not specify by whom.

A panel of investigators from the United Nations and the Organization for the Prohibition of Chemical Weapons submitted the report on Wednesday to members of the United Nations Security Council. It was not made public, but a copy was viewed by The New York Times. [Continue reading…]