Nato warplanes struck Tripoli today in the heaviest bombing of the capital in weeks.
At least four sites were hit in the capital. One hit a building used by a military intelligence agency. Another targeted a government building sometimes used by parliament members.
Another produced plumes of smoke that appeared to come from the compound housing members of Muammar Gaddafi's family.
The intensified air campaign comes as Nato faces criticism for not doing enough to break Gaddafi's grip.
The Tripoli bombing came just hours after heavy fighting was reported on the eastern front, south of Ajdabiya, a rebel-held town about 90 miles south of Benghazi, the rebel headquarters in the east.
Rebel commander Zakaria al-Mismari said that Gaddafi forces had advanced on their positions with about a dozen vehicles. "By God's grace we managed to defeat them and outflank them, and we attacked 12 of their vehicles," he said.
The rebels said they had retreated because they were told Nato was launching airstrikes against Gaddafi forces there.
The rebels were deliberately vague about where the front is, some saying the fighting had taken place 12 to 25 miles from Ajdabiya, others placing it nearer to the oil town of Brega.
The rebel army has been bogged down for weeks near Ajdabiya, unable to move on to Brega, which has an oil terminal and Libya's second-largest hydrocarbon complex.
The rebels say their weapons cannot reach more than about 12 miles while Gaddafi's forces can fire rockets and shells up to twice that distance. Rebel pleas for heavier arms from abroad have received no response.
Gaddafi's forces also shelled a northern Misrata district where many families from the besieged city centre have fled, one rebel said.
The fighting was threatening the port area, the city's only lifeline, preventing some aid ships from docking, he said.
One ship carrying medical supplies and baby food was able to dock, the first ship to arrive since last Wednesday, when Gaddafi's forces fired a barrage of rockets into the port as the International Organisation of Migration was evacuating nearly 1,000 people.
The UN refugee agency, meanwhile, appealed to European countries to step up efforts to rescue people fleeing Libya in overloaded boats.
A spokeswoman for the UN High Commissioner for Refugees said that "any boat that is leaving Libya should be considered, at first glance, as a boat in need of assistance."
She said the agency had been told 16 bodies including those of two babies have so far been retrieved from a boat carrying 600 people that sank just outside the Libyan capital on Friday.Reuse content