The United Nations' report on the alleged August 21 chemical weapons attack in a suburb of Damacus suggests that it was not just alleged. Calling the attack a "war crime," Secretary General Ban Ki-Moon noted that evidence of the use of sarin gas was "overwhelming and indisputable." By whom, however, isn't specified.
Ban presented the report to the United Nations Security Council in a private meeting on Monday morning, but made his remarks available to the public. The report itself, also available online, walks through the evidence collected and analyzed by the UN team that was already in the country researching another alleged use of outlawed weapons when the August 21 attack occurred.
The Mission has concluded that chemical weapons were used on a relatively large scale in the Ghouta area of Damascus in the context of the ongoing conflict in Syria. The attack resulted in numerous casualties, particularly among civilians. …
Survivors reported that following an attack with shelling, they quickly experienced a range of symptoms, including shortness of breath, disorientation, eye irritation, blurred vision, nausea, vomiting and general weakness. Many eventually lost consciousness. First responders described seeing a large number of individuals lying on the ground, many of them dead or unconscious.
The report itself includes 30 data points, walking through weather conditions, medical evidence, and photographic details of the surface-to-surface rockets that carried the weapons. While the team was limited "due to the security situation" (in Ban's words), its point is direct. The 30th data point simply reads, "This result leaves us with the deepest concern."