Armed groups in Libya are abducting and torturing civilians, the United Nations said Friday, warning that such actions are "war crimes".
"Armed groups across Libya are responsible for abductions of civilians, including minors, on account of their actual or perceived origin, opinion, family and political affiliation," the UN Support Mission in Libya (UNSMIL) said in a statement.
"Those abducted are usually at risk of torture and other ill-treatment, and are frequently denied any contact with their families. Some have died in custody, possibly summarily executed or tortured to death."
Libya plunged into lawlessness after the 2011 NATO-backed uprising that toppled dictator Moamer Kadhafi, with armed groups battling for control of the North African country's oil wealth and cities.
The chaos has been further compounded with the country politically divided, with rival governments and parliaments vying for power and the Islamic State group also spreading its influence.
"Hostage-taking, torture and murder are war crimes," said UNSMIL, which is trying to mediate a settlement to the crisis.
"Those responsible for committing, ordering or failing to prevent such crimes when in a position to do so are criminally liable, including in front of the International Criminal Court."
ICC chief prosecutor Fatou Bensouda told the UN Security Council on Tuesday that she was ready to investigate crimes committed by IS in Libya, where the group said it has beheaded dozens of Christians.
Rights groups have repeatedly bemoaned violations of human rights in Libya, with activists and journalists the target of armed groups since the end of the 2011 revolt.
A report drafted by the UN rights office and UNSMIL and released on March 25 said activists speaking out against abuses faced reprisals from all sides, and that many have been killed.
Claudio Cordone, head of UNSMIL's human rights division, said at the time there were an estimated 200,000 to 300,000 people armed people in Libya, 10 times more than those who fought in the uprising.
On March 27, the 47-member UN Human Rights Council adopted by consensus a resolution to send a mission to the country to investigate violations and abuses.