A mass grave has been found in an Aleppo district previously controlled by the so-called ’Islamic State of Iraq and the Levant (ISIL)’ terrorist group.

A mass grave has been found in an Aleppo district previously controlled by the so-called 'Islamic State of Iraq and the Levant (ISIL)' terrorist group, activists said Friday.

A UK-based Syrian Observatory for Human Rights (SNHR) spokesman, Ahmad Mohammad Ali, told Anadolu Agency that other possible mass graves were also discovered in Aleppo's Azzaz district in the wake of ISIL's withdrawal from the area.

Ali also said ten corpses were removed in the Jabal Bursaya region in northern Aleppo.

A recent Observatory report said ISIL was responsible for killing nearly 200 civilians and arresting over 2,000 over an eight-month period up to January.

The group has very tensed relations with many factions among the Syria opposition armed groups.

Syria was hit by a violent unrest since mid-March 2011, where the Syrian government accuses foreign actors, mainly the Saudi Arabia, of orchestrating the conflict by supporting the militant opposition groups with arms and money.