DAMASCUS, Dec. 13 (CGTN) -- Seven mass graves containing hundreds of unidentified bodies have been unearthed near the former ISIL stronghold of Albu Kamal in eastern Syria, Syrian state media SANA reported.

Most of the more than 100 bodies recovered so far at the site appear to "have been subjected to torture and ill-treatment before execution", it said, accusing ISIL of killing the victims.

Work was underway to retrieve the rest of the bodies from the graves in the eastern province of Deir Ezzor, SANA said on December 11.

It released a video showing forensic experts in protective clothing recovering remains, and corpses laid out on the ground in a row under white sheets.

"After examining the remains, it appears that most of the people were executed by bullets to the head, while their hands were tied," said an unidentified member of the military who appears in the video.

ISIL has been held responsible for multiple atrocities during its reign of terror, including mass executions and decapitations.

In recent months, both Syria and Iraq have discovered a number of mass graves in areas previously occupied by the jihadists.