Heavy artillery fire rocked the Libyan town of Sirte Saturday as provisional government fighters battled former leader Moammar Gadhafi's loyalists.

National Transitional Council fighters pushed into the town's center earlier this week but have been facing stiff resistance from snipers and other pro-Gadhafi forces.

The provisional fighters are also trying to gain the upper hand in Bani Walid, a desert town that is among the few remaining strongholds for Mr. Gadhafi's supporters.

The NTC is meeting Saturday to discuss the formation of a new interim government. An NTC spokesman says the government will include 22 ministers and a deputy prime minister.

Mr. Gadhafi's whereabouts remain unknown. On Friday, his daughter, Aisha Gadhafi, released an audio recording in which she says her father was in high spirits and fighting alongside his supporters.

The message was aired by Syria-based Arrai television. Aisha Gadhafi called the country's new leaders “traitors” because some of them had been part of the Gadhafi government.

Aisha, her mother and two brothers fled to Algeria in August as NTC fighters swept into Tripoli.