At least 30 Syrian soldiers were killed Wednesday in an attack by the jihadist Islamic State group on their bus in the east of the war-torn country, a monitor said.

The Syrian Observatory for Human Rights said the attack in Deir Ezzor province targeted a bus carrying regime soldiers going home on leave. The official news agency SANA reported that a "terrorist attack" on a bus killed "25 citizens" and wounded 13. Abdel Rahman said the bus was ambushed near the village of Shula by jihadists who detonated bombs before opening fire. Two other buses which were part of the convoy managed to escape, the war monitor said. There was no immediate claim of responsibility for the attack.