A ceasefire in Syria appears fragile after government forces and their allies clashed with rebels.

The fighting near Damascus threatens to derail the nationwide truce agreed between President Assad's regime and thousands of opposition fighters.

Helicopter gunships were reportedly used during raids in a rebel-held valley northwest of the capital.

The ceasefire came into effect last night and appears to have held in most other areas.

The truce has been arranged by Russia and Turkey, in a bid to explore political solutions to the ongoing Syrian war.

Security Expert Shashank Joshi says it's interesting how far the main parties have come over the past few months: