The rebels were also criticised in the report UN Libya team accuses both sides
The rebels were also criticised in the report UN investigators have accused government forces in Libya of war crimes and crimes against humanity.
Rights experts said they found evidence of crimes including murder and torture, in a pattern that suggested Libyan leader Muammar Gaddafi was behind them.
The UN mission also said opposition forces were guilty of abuses which would constitute war crimes, although they were not as numerous.
Earlier Nato extended its mission in Libya by a further 90 days.
Nato is enforcing a UN resolution to protect civilians in Libya amid a two-month revolt inspired by other uprisings in the Arab world.
The UN report, which has just been released in Geneva, was carried out by a team of three human rights experts.
The team travelled to Libya to carry out the investigation, and met both sides in the conflict, as well as human rights groups and medical professionals, and families of those detained.
The report will be debated by the UN human rights council in Geneva on Monday.
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