Three months after Muammar Gaddafi was ousted from power in Libya, outside groups are expressing increased concerns about the torture of prisoners and just who is behind the mistreatment.

Amnesty International said several people have died after being tortured in detention centers, and French medical charity Medecins Sans Frontieres — Doctors Without Borders — suspended operations in the city of Misrata after treating more than 100 patients with what the group’s general director called “torture related wounds.”

The director of the group said it's been happening more often and has been so egregious as to include torture victims being brought to them for treatment, only to be returned for interrogation and further torture the same evening.

Gabriel Gatehouse, BBC reporter, said there are about 1,000 detainees at the facility in Misrata that has caused the abuse that caused MSF to leave. Most of them, Gatehouse said, have no idea why they're being held.

"A few of them said they'd fought on the side of Col. Gaddafi, but most of them said they just thought they wer victims of racism, they'd been there because they were Black Africans who many of the rebels thought of as rebels fighting for Col. Gaddafi, or they simply came from towns that were thought to have fought on the regime's side," Gatehouse said.

Gatehouse said he heard horrific tales of abuse not at the detention center itself but of prisoners who are being held there and are taken to Army headquarters where they were beaten or subjected to electric shocks, before being brought back to the detention center.

Both government forces as well as independent militias are accused of torturing their detainees, though the head of the Libyan military in Misrata completely denied there was any torture being perpetrated by his forces.

"He said any wounds I might have seen must have been related to the conflict," Gatehouse said. "They're from NATO airstrikes or the fighting."

MSF said the injuries were consistent with torture — not with war wounds.

On the militia front, in a community south of Tripoli, men say they were founded up by local fighters, after minor clashes erupted, and tortured.

"It seemed to have been sparked by a very small disagreement between young men," Gatehouse said. "We understand the miltia took over 20 men prisoner and tortured all of them."

One man described sustained beatings that lasted until he passed out, while another man, who was also taken at the same time, died and his bodies shows signs of massive bruising. A nurse who was present at the autopsy said the man appeared to have been subjected to repeated electrical shocks.

The Libyan central government has struggled to assume control over what is still a very fractured country. In many places, local leaders operate without guidance from or interference by national authorities.

"There's a limit to what authorities in Tripoli can do to stamp their authority on these kinds of situations," Gatehouse said.