The United Nations has accused government and opposition forces of rights abuses in Libya.
A report by three UN-appointed experts called on both sides to conduct transparent and
exhaustive investigations and bring those responsible to justice.
Earlier, Nato extended its Libyan mission for a further 90 days, after Muammar Gadafy made it clear he would not step down, ending hopes of a negotiated end to the uprising against his rule.
The 28-member alliance originally took over a campaign of air strikes, the enforcement of a no-fly zone and an arms embargo on Libya, to protect rebellious civilians from attack by Col Gadafy's forces, in late March for 90 days.
"Nato and partners have just decided to extend our mission for Libya for another 90 days," Nato secretary-general Anders Fogh Rasmussen said in a statement. "This decision sends a clear message to the Gadafy regime: We are determined to continue our operation to protect the people of Libya."
The head of Libya's National Oil Corporation Shokri Ghanem said today he had defected from the government but had not yet decided whether to join anti-Gadafy rebels.
Speaking at a news conference in Rome organised by the Libyan ambassador, who has also defected, Mr Ghanem said he had left his job because of the "unbearable" violence in Libya.
He said he still saw some possibility of a peaceful settlement to decide the fate of the Gadafy rule, which he had left because of the "daily spilling of blood" he had witnessed in Libya.
Mr Ghanem, who is one of the most senior Libyan officials to have defected, said he supported "Libyan youth fighting for a constitutional state."
South African president Jacob Zuma said yesterday after talks with the leader that Col Gadafy had stated emphatically he would not leave Libya - making a negotiated end to the conflict impossible given rebel demands for his departure.
Mr Zuma was in Tripoli on Monday to try to revive an African "roadmap" for ending the conflict, which started in February with an uprising against the Gadafy regime and has since turned into a war in which thousands of people have been killed.
Nato has echoed rebel demands that set Col Gadafy's departure as the main condition for any cease-fire.
New questions arose over how long Col Gadafy could hold on after a senior United Nations aid official said food and medicine shortages in Gadafy-controlled areas amounted to a "time bomb."
Panos Moumtzis, the UN humanitarian coordinator for Libya, said yesterday that some food stocks in areas under Col Gadafy's control were likely to last only weeks.
"I don't think there's any famine, malnutrition. But the longer the conflict lasts the more the food stocks are going to be depleted, and it's a matter of weeks before the country reaches a critical situation," Mr Moumtzis said. "The food and the medical supplies is a little bit like a time bomb. At the moment it's under contol and it's OK. But if this goes on for quite some time, this will become a major issue."
Also casting doubt on Col Gadafy's assertions that he is in control, witnesses said yesterday that a large anti-government protest had taken place on Monday in the Souq al-Juma suburb of Tripoli.
The protest, apparently the biggest confirmed in Tripoli since Western forces began bombing the country in March, was broken up by security forces firing weapons, residents said.
Asked about the incident at a news conference yesterday, government spokesman Moussa Ibrahim said: "I have heard of the event. I did not have enough time to get information."
There have been no large-scale demonstrations in Tripoli since protests were crushed by the security forces in February.
Now in its fourth month, the Libyan conflict is deadlocked, with rebels unable to break out of their strongholds and advance towards Tripoli, where Col Gadafy appears to be firmly entrenched.
Rebels control the east of Libya around the city of Benghazi, the third-biggest city Misrata, and a mountain range stretching from the town of Zintan, 150km south of Tripoli, towards the border with Tunisia.
Col Gadafy, in power for 41 years, says his forces are fighting armed criminal gangs and al-Qaeda militants and portrays the Nato intervention as an act of colonial aggression aimed at seizing Libya's oil reserves.
His government says Nato's bombing campaign has killed 718 Libyan civilians and wounded 4,067, of whom 433 it says have been seriously wounded.
Libya's state news agency Jana reported today that Nato airstrikes hit the town of Al Jufra, about 460km southwest of Tripoli, early in the morning.
Nato has denied killing large numbers of civilians, and foreign reporters in Tripoli have not been shown evidence of large numbers of civilian casualties.
Reuters