Fighters from the Islamic State in Iraq and the Levant (Isis) say they have overrun a large Syrian military base on the outskirts of the city of Raqqa.
The Islamist fighters have released images of captured soldiers being beheaded after the battle for the base.
The Syrian army did not confirm that the base had fallen, but said it was organising a counter-attack.
Isis already controls much of Raqqa province, and recently seized a swathe of territory in neighbouring Iraq.