BEIRUT: Syrian activists say fresh fighting has broken out in the southern city of Daraa between the rebels and pro-government forces.

Local opposition activist Ahmad al-Masalmeh says pro-government forces pounded the divided city with airstrikes and artillery fire on Sunday, one day after rebels attacked government positions.

The Britain-based Syrian Observatory for Human Rights says at least three different parts of the city have come under rocket and missile attack by government forces, and that rebels are returning fire.

Syrian military media distributed footage showing its planes and artillery striking built up areas.

Daraa is understood to lie within four "de-escalation" zones around Syria, where Russia, Turkey, and Iran have guaranteed cease-fires between the warring parties. The precise boundaries of the zones are unclear.