The attack takes place as a graduation ceremony comes to an end, Syria’s military says.

Drones laden with explosives targeted the ceremony on Thursday as it came to an end, Syria’s military said in a statement. They accused fighters “backed by known international forces” for the attack.

The statement did not specify the number of casualties but said some of the wounded were in critical condition, including women and children. There was no immediate claim of responsibility.

Syria’s defence minister attended the graduation ceremony but left minutes before the attack, the Reuters news agency reported, citing a Syrian security source and a source in the regional alliance backing the Damascus government against opposition groups.

“After the ceremony, people went down to the courtyard and the explosives hit. We don’t know where it came from, and corpses littered the ground,” said a Syrian man who had helped set up decorations at the ceremony.