“We have raised the banner ‘There is no God but God’ above the houses of the apostate rejectionists, the Shi’ites, and the holy warriors are celebrating,” the voice of the cameraman says.

Many of the fighters involved in the attack were said to be from the al Qaeda-linked Nusra Front. Hardline Sunni groups often refer to Shi’ites as rejectionists because they deny the legitimacy of the Prophet Mohammad’s first successors.

“This is a Sunni area, it does not belong to other groups,” one fighter shouted in the video purportedly filmed in the town of Hatla in the eastern province of Deir al-Zor.