After it evacuated 12 international staffers in Tripoli due to unrest in parts of the city, the UN is exploring ways to get back into the Libyan capital.
"The UN is exploring ways to re-enter the Libyan capital as soon as possible," UN spokesperson Martin Nesirky has said.
Nesirky said humanitarian work is continuing, with the redeployed staff from Tripoli supporting operations in western Libya from Tunisia. The UN national staff remained in Tripoli.
There are also international staffers in the rebel-held town of Benghazi.
After it emerged that Muammar Gaddafi's youngest son Saif al-Arab and three of his grandchildren had been killed in a NATO air strike, the UN compound reportedly was attacked by a mob, but none of the staff were hurt.
The residences of British and Italian were also burnt.
The office for the Coordination of Humanitarian Affairs said that more than 665,000 people have now fled strife-torn Libya.