Daesh has executed nearly 20 people including two children in a village in Syria's eastern Deir al-Zor city, and captured fighters participating in a US-backed operation against the militants, a British-based monitoring group said on Saturday.
The Syrian Observatory for Human Rights (SOHR) said that Daesh had raided the village of Jizrat al-Boushams, northwest of Deir al-Zor city near the provincial boundary with Raqqa on Friday.
SOHR posted a video showing the corpses of around a dozen men who had apparently been shot.
Daesh withdrew from the village after the attack taking the captured fighters, it said.
The ultra-hardline group has staged attacks on villages near areas it controls as it is being pushed back towards its strongholds of Raqqa and Deir al-Zor.
Separate forces are fighting the group, which is the enemy of all other sides in the Syrian conflict.
Syria has been facing a civil war since 2011 after regime forces launched a crackdown on pro-democratic protesters.
The conflict has so far claimed over 400,000 lives and led to one of the world's worst refugee and humanitarian crisis with millions of people displaced.