DAMASCUS, Dec. 11 (Xinhua) -- The Syrian authorities have uncovered seven mass graves with hundreds of bodies in a former Islamic State (IS) stronghold in eastern Syria, state news agency SANA reported on Tuesday.

Hundreds of unidentified bodies were found in the mass graves in the city of Abu Kamal in the southeastern countryside of Deir al-Zour province in eastern Syria, according to SANA.

The report said the bodies belong to those who were executed by IS when the group controlled the area.

So far, the civil defense units in cooperation with the Syrian Arab Red Crescent have unearthed 101 bodies, most of which had marks of torture, said the report, adding that work is underway to unearth the rest.

The Syrian army captured Abu Kamal from IS in 2017 as the area was a key bastion of the terror-designated group near the Iraqi border.