The United Nations' humanitarian chief says 750,000 people have fled Libya since Muammar Gaddafi'S forces began a crackdown on anti-government demonstrators.
Valerie Amos has told the Security Council the three-month-old conflict, the breakdown of state infrastructure and cash and fuel shortages are paralysing the country.
The UN can't put an accurate figure on casualties, but more than 746,000 people have fled the country, about 5000 are stranded at border points in Egypt, Tunisia and Niger and about
58,000 are displaced in eastern Libya, Amos said.
Amos says the concern now is rebel-held Misrata where basic supplies are running out and hundreds are said to have been killed by Gaddafi's troops in the last couple of months.
"The conflict, the breakdown of state infrastructure and shortages of cash and fuel are causing serious problems to the population of Libya," Amos said.
"Widespread shortages are paralysing the country in ways which will impact gravely on the general population in the months ahead, particularly for the poorest and the most vulnerable," Amos told ambassadors from the 15-nation council.
UN humanitarian workers were pulled out of Tripoli after the UN compound was ransacked on May 1, just after a coalition air raid which killed one of Gaddafi's sons.
"The government has apologised for the incident and offered full compensation for the damage caused," Amos said, adding that new security guarantees had been given by the government.
"It is our intention to return as soon as possible to Tripoli and open land access to Misrata, the western mountains and other affected areas."
Rebel-held Misrata has been under attack by Gaddafi forces for more than two months and hundreds are said to have been killed there.
"Some people are running short of food, water and other basics. Medical facilities need supplies and trained personnel," Amos said.
More than 13,000 people have been evacuated from the western city, which normally has a population of about 300,000, but Amos said up to 300 third country nationals are still stranded there.
The UN has appealed for about $US300 million ($A280.2 million) for its Libyan humanitarian operation and has so far received about $US144 million ($A134.5 million), Amos said.
The news came as NATO jets screamed in low over Tripoli early on Tuesday, carrying out a up to eight strikes in quick succession, after witnesses reported two others near state media offices a few hours before.
