Libya Febrayer TV yesterday aired a video showing detention facilities, which it described as "human ovens", where oppositionists were tortured by renegade General Khalifa Haftar's forces.
The video showed very narrow cells located in the city of Tarhuna, south-east of the capital, Tripoli, with steel doors.
The channel commented on the footage, saying: "Very narrow cells were used by the Tarhuna-based Al-Kani terrorist militia, affiliated with Haftar's forces, to lock down prisoners and then set fire to its ceilings."
One of the activists said these cells "look like the ovens that Hitler used to burn the Jews," while another referred to what happened as "Libya's Holocaust".
On Tuesday, the International Criminal Court (ICC) agreed to send a team to investigate Haftar's crimes in Tarhuna.
Since the internationally backed Libyan Government of National Accord (GNA) liberated the areas around Tripoli, mass graves containing the bodies of more than 200 bodies have been discovered in areas previously controlled by Haftar's militia.