Syrian government air strikes killed at least 10 civilians Thursday in the worst ceasefire violation yet in a key rebel bastion east of the capital, a monitoring group said, according to AFP.

Dozens more were wounded in the raids on Deir Al-Assafir, a town in the opposition stronghold of Eastern Ghouta, the Syrian Observatory for Human Rights said.

The toll, which included two children and a civil defense volunteer, represented "the largest ceasefire violation in Eastern Ghouta," Observatory head Rami Abdel Rahman said.