Nato warplanes have struck Tripoli 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.
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.