UNITED NATIONS — Careful not to blame either side for a deadly chemical weapon attack, U.N. inspectors reported Monday that rockets loaded with the nerve agent sarin had been fired from an area where Syria's military has bases, but said the evidence could have been manipulated in the rebel-controlled stricken neighborhoods.
The U.S., Britain and France jumped on evidence in the report — especially the type of rockets, the composition of the sarin agent, and trajectory of the missiles — to declare that President Bashar Assad's government was responsible.
Russia, Syria's closest ally, called the investigators' findings "deeply disturbing," but said it was too early to draw conclusions. The Syrian government's claims that opposition forces were responsible for the attack "cannot be simply shrugged off," Russian Ambassador Vitaly Churkin insisted.
The conclusions represented the first official confirmation by impartial scientific experts that chemical weapons were used in Syria's civil war, but the inspectors' limited mandate barred them from identifying who was responsible for the Aug. 21 attack.
"This is a war crime," U.N. Secretary-General Ban Ki-moon told the Security Council when he presented the report. "The results are overwhelming and indisputable. The facts speak for themselves."
Ban called it "the most significant confirmed use of chemical weapons against civilians since Saddam Hussein used them" in Halabja, Iran, in 1988, and "the worst use of weapons of mass destruction in the 21st century."
The deep division between Western backers of rebels seeking to overthrow Assad and Russian and Chinese supporters of the regime has paralyzed the U.N. Security Council since the Syrian conflict began 2 1/2 years ago.
Even though the United States and Russia agreed Saturday on the framework to put Syria's chemical weapons stockpile and precursors under international control for future destruction, their top diplomats were at odds Monday over a new Security Council resolution that would make the deal legally binding — and whether there should be a reference to possible military enforcement if Syria doesn't comply.