Syria: Isis Advance on Aleppo Aided by Assad Regime Air Strikes

The US has accused the Syrian government of providing air support to an advance by Islamic State militants against opposition groups north of Aleppo.
Fighters opposing Syrian leader Bashar al-Assad have made the same claims since Sunday, when Isis began advancing towards the town of Azaz near the Turkish border.
The seizure of Azaz, some 20 miles north-west of Aleppo, would imperil the main opposition supply line into Syria’s biggest city, the rebel-held east of which has been besieged by government forces for more than two years.