Libyan officials and medics say two people have been killed by apparent NATO airstrikes in Tripoli.
Witnesses say several large explosions rocked the capital on Thursday. Libyan government officials say at least four rockets targeted a compound in the city that belongs to leader Moammar Gadhafi.
Also, a Libyan state television report says the North Korean embassy in Tripoli was damaged in a NATO airstrike.
Meanwhile, Britain has invited the Libyan opposition to open an office in London. Prime Minister David Cameron announced the decision on Thursday after meeting with Mustafa Abdel-Jalil, the head of Libya's opposition National Transition Council (NTC).
Ahead of the meeting, Britain's Foreign Office said officials would also discuss a proposal to provide more non-lethal aide to Libyan rebels.
The efforts come a day after a U.S. lawmaker announced plans to help the NTC. Senator John Kerry said Wednesday that he was drafting legislation to authorize the transfer Gadhafi's frozen assets to the opposition council. Kerry, who chairs the foreign relations committee, did not disclose the amount but said it would be enough to impact the crises faced by the council.
Libyan rebels in the besieged western city of Misrata said they had taken control of the municipal airport on Wednesday, following days of heavy fighting. The rebels said they seized large quantities of weapons and ammunition.
Opposition military sources in Misrata, including the commander at the airport, said the rebels had secured the entire facility, which had become the main base for pro-Gadhafi forces in the city.
Later Wednesday, Gadhafi made his first television appearance since a NATO airstrike on a house in Tripoli killed one of his sons and three grandchildren on April 30. Libyan state television filmed him at a brief meeting with tribal leaders. A projection screen behind Gadhafi showed Wednesday's date.
In another development, the U.S.-based GlobalPost news agency says two U.S. journalists detained by pro-Gadhafi forces in Libya have received their first visits since being taken into custody last month. Agency officials said Wednesday intermediaries had been allowed to meet with James Foley and Clare Morgana Gillis in Tripoli.