The United Nations has called an end to its military observer mission in Syria, days before its mandate was due to end, France says.

"The conditions to continue UNSMIS were not filled," France's UN ambassador Gerard Araud said after a Security Council meeting.

Russia warned earlier that pulling out of Syria would have "serious negative consequences" for the region.

The UN mission had been part of envoy Kofi Annan's six-point peace plan.

But continuing violence made the observers' mission increasingly difficult and a bomb exploded close to their hotel in Damascus on Wednesday. Mr Annan resigned as UN-Arab League envoy to Syria a fortnight ago, complaining of a "clear lack of unity" in the Security Council.

Although the 101 remaining military observers will leave Damascus over the next eight days, a civilian liaison office is due to remain and a new special envoy is expected to be appointed.