Rebels say they have begun a new battle in north-western Syria in response to alleged truce violations by the army, BBC News reports.

A statement announced the formation of a joint operations room following what it said was an increase in attacks on residential areas and displaced people.

Rebels were said to have subsequently launched attacks in the province of Latakia and in neighbouring Hama.

The rebels also urged opposition negotiators in Geneva to take a tougher stand at UN-led peace talks.

The cessation of hostilities brokered by the U.S. and Russia to make way for the talks has resulted in a significant reduction in violence since it took effect on 27 February.

But escalating fighting in recent days, particularly around the divided northern city of Aleppo, has left it on the verge of collapse.