Russia's foreign ministry has said that if the United Nations were to pull out of Syria, it would have "serious negative consequences" for the region, BBC News reported.

The warning comes as the UN prepares to formally end its observer mission in Syria.

The mission's mandate expires on Sunday, August 19 and the UN has said the continuing violence means it will not be renewed.

Fresh fighting was reported in Aleppo on Thursday, with dozens reported killed in an attack on a bakery.

Meanwhile more details have emerged of an air strike on the nearby town of Azaz, close to the Turkish border, on Wednesday. The US-based group Human Rights Watch (HRW) says 40 people are now known to have died there.

The strike injured more than 100 people, said HRW, and destroyed an entire block of housing. Many of the wounded are reported to have been taken to Turkey for treatment.