Ground fighting raged in Libya on Tuesday and an American fighter jet crashed overnight in the first known setback for the international coalition attacking forces loyal to Muammar Gaddafi.
Gaddafi's forces attacked two west Libyan towns, killing dozens while rebels were pinned down in the east and NATO tried to resolve a heated row over who should lead the Western air campaign.
With anti-Gaddafi rebels struggling to create a command structure that can capitalise on the air strikes against Libyan tanks, Western nations have still to decide who will take over command once Washington pulls back in a few days.
In the latest fighting on Tuesday, Gaddafi's tanks shelled the rebel-held western town of Misrata and casualties included four children killed when their car was hit, residents said, adding the death toll for Monday alone had reached 40.
Gaddafi forces also were trying to seize the western rebel-held town of Zintan in an attack using heavy weapons, and one resident said 10 people were killed on Tuesday.
Residents painted a grim picture of the situation in Misrata which has been under siege by Gaddafi loyalists for weeks, with doctors operating on people with bullet and shrapnel wounds in hospital corridors and tanks in the city centre.
In the first apparent air force casualty of the campaign, a US F-15E crashed in Libya overnight and its two crew members were rescued, the US military said.
The crash was likely caused by mechanical failure and not hostile fire, it said.
Explosions and anti-aircraft rounds rang out around Tripoli for a third time overnight, and Libyan state television said several sites in the capital had come under attack by what it called the "crusader enemy".