BEIRUT: Air and missile strikes on a school district and other areas in insurgent-controlled Damascus suburbs killed at least 31 people on Sunday, including three children and a school principal, a group monitoring the Syrian war said.

The Syrian Observatory for Human Rights said unidentified warplanes hit the town of Douma, 15 km northeast of the capital, and surface-to-surface missiles fired by the Syrian army also hit the surrounding areas, including Eastern Ghouta.

The areas have been under heavy bombardment in recent months. The Syrian Army has said its strikes target insurgents that have launched attacks on government-held areas.

The Observatory, which gathers information from a network of contacts on the ground, said at least 40 mortar bombs fired by insurgents in the eastern suburbs hit Damascus on Sunday, killing at least one child and wounding several.

The civilians were killed in mortar attacks targeting residential neighborhoods of Damascus. Most of the victims were school students, it said, citing its reporter in the area.