Footage on social media showed fighters from the self-styled army in eastern Libya - under the command of Khalifa Haftar - mutilating bodies of dead fighters from the Derna Protection Force (DPF.)

According to the videos, the fighters exhumed several graves of their foes and then set them ablaze, including the body of journalist Yousif Bin Khayal, who was killed two months ago. Bin Khayal fought ISIS in Derna in 2016.

The east-based Interim Government said on Facebook on Monday that military operations in Derna had ended after "cleansing it from all terrorists."

"We have liberated Derna despite the siege of the international community on our force and the ban of arms. We have defeated terrorists and extremists in eastern Libya." The Interim Government said.

According to Haftar, Derna was announced "liberated" from all "terrorist fighters" last June.

In the meantime, media sources close to DPF said five of the force's leaders were killed in clashes at the old city's frontline.

The leaders included Adnan Al-Shaari, Mohammed Dango, and the DPF's spokesman Mohammed Al-Mansouri.

Over the last days, clashes between the DPF and the fighters of Haftar's self-styled army were at height in Wasat Al-Blad and old town areas, which were the last bastions of the DPF's fighters.

Mutilating bodies, exhuming graves, burning bodies and more have been seen before by Haftar's forces in Benghazi's Ganfouda and elsewhere in 2017.