The UK-based rights organisation, Amnesty International, has accused Libyan armed groups now ruling much of the country of committing widespread abuses, saying suspected supporters of former ruler Muammar Gaddafi are being tortured with impunity.
In a report released on Wednesday, Amnesty said the ruling National Transitional Council (NTC) has failed to control the fighters.
It said it had documented widespread abuses, including war crimes, with people being unlawfully detained and tortured, sometimes even to death.
“Militias in Libya are largely out of control and the blanket impunity they enjoy only encourages further abuses and perpetuates instability and insecurity,” Donatella Rovera, senior crisis response adviser at Amnesty, said.
Rights groups have repeatedly raised concerns about torture being used against people, many of them sub-Saharan Africans, suspected of having fought on the side of Gaddafi's forces during Libya's nine-month civil war which ended in October.
Tortured to death
Amnesty said its delegates in January and earlier this month visited 11 detention facilities used by various armed groups and at 10 of these locations, detainees said they had been tortured or ill-treated, and had injuries resulting from recent abuse.
At least 12 detainees held by such groups had died after being tortured since September, the group said.
The group said one of its delegates had seen armed militia members beating and threatening some detainees whose release had been ordered in the town of Misurata.
"An older detainee from Tawargha was cowering, squatting against the wall, and crying as he was being kicked and threatened by a militia member who told Amnesty International that 'those from Tawargha will not be released or we’ll kill them'," the report said.
Gaddafi's forces used Tawargha as a base for attacks on Misurata when they besieged the city during the uprising and fighters accuse its residents, many of them non-Arab Libyans, of committing atrocities.
Since the war's end with the capture and killing of Gaddafi last October, the NTC has struggled to extend its control over the vast desert nation. It has largely failed to rein in the hundreds of brigades that fought in the war, many of which now run their own detention centres for those accused of links to Gaddafi's regime.
About 2,400 detainees remain held in centres controlled by the new Libyan government, but the militias are holding uncounted thousands more prisoners, Amnesty said.
Most are in and around Tripoli and Misrata, the coastal city that saw some of the war's most brutal fighting, it said.
The UN's top human rights official had also called on the Libyan authorities to take control of all makeshift prisons to prevent further atrocities against detainees.
"There's torture, extrajudicial executions, rape of both men and women,'' Navi Pillay, UN High Commissioner for Human Rights, said on January 27.
Last month, Libya's former ambassador to France appeared to have died of torture after being detained by an armed group in Tripoli, another rights group said.
A preliminary autopsy report obtained by the New York-based Human Rights Watch, and photographs provided by Omar Brebesh's family, showed that the cause of his death was "multiple bodily injuries and fractured ribs".
His body was marked by welts, cuts and the apparent removal of toe nails.
Aid agency Medecins Sans Frontieres has halted its work in detention centres in Misrata because it said its medical staff were being asked to patch up detainees mid-way through torture sessions so they could go back for more abuse.