Sirte, one of the last two bastions of support for Gaddafi, is encircled by forces with the interim National Transitional Council (NTC) and under aerial attack from NATO.

NTC fighters have been meeting stiff resistance from Gaddafi loyalists, who have managed to hang on to much of Sirte more than a month after the fall of the Libyan leader's regime.

Lack of coordination and divisions at the front have been hampering their attempts to capture Sirte and Bani Walid, which lies 180 km (110 miles) south of Tripoli.

There were clashes at a roundabout 2 km (1.5 miles) east of the center of Sirte, where anti-Gaddafi fighters were pinned down for a second day by sniper and artillery fire.

Forces with the new government brought in two tanks and trucks carrying infantry to try to break through.

Snipers, though, held up the advance, forcing the attackers to take cover behind metal shipping containers.

Medical workers at a hospital in Ras Lanuf, which lies 220 km (137 miles) east of Sirte, said they had received the bodies of six NTC fighters killed in fighting on the city's eastern front. Some 45 fighters were wounded, many from sniper fire.