Syrian forces loyal to President Bashar al-Assad carried out a "massive and co-ordinated" chemical attack on August 21, one of "at least three" this year, a declassified French intelligence report concluded yesterday.
The nine-page intelligence document, published on government websites, detailed five points suggesting pro-Assad fighters were behind the assault.
Satellite images showed strikes coming from government-controlled areas to the east and west of the Syrian capital and targeting rebel-held zones - areas that had since been bombed to wipe out evidence, the report concluded.
"The attack of August 21 can only have been carried out by the regime. Unlike previous attacks that used small amounts of chemicals and were aimed at terrorising people, this attack was tactical and aimed at regaining territory."
About 47 amateur video clips reportedly filmed on the morning of the attack and showing the impact on civilians had been authenticated by French military doctors, according to the intelligence. Video evidence alone showed that at least 281 people died in the attack but the real figure was more likely to be about 1500, it said.