Loud explosions and barrages of anti-aircraft fire were heard again this evening in Tripoli and the port city of Sirte.
In Tripoli, firing was heard near the compound of Libyan leader Muammar Gaddafi and near the Bab el-Aziziya barracks in the south, while in Sirte, the airport was believed to be under attack.
Meanwhile a spokesman for the Gaddafi government said the town of Misrata, scene of fierce fighting over the past few days, was under the government's control.
Britain, France and the US began launching strikes with aircraft and cruise missiles on targets in Libya late on Saturday in line with a UN Security Council resolution authorising any measures to stop Gaddafi harming civilians in a campaign by his forces to subdue an uprising.