Libya Uprising: Gaddafi 'Losing Control Of Sabha'
Libya's interim rulers, the National Transitional Council, say their forces have now taken control of much of the city of Sabha, 750km (465 miles) south of Tripoli.
They said they had reached the city centre but that there was still resistance in some districts.
Sabha was considered one of the key remaining strongholds of fugitive leader Col Muammar Gaddafi's forces.
Fierce fighting continues at other Gaddafi hold-outs Bani Walid and Sirte.
NTC military spokesman Ahmed Bani told Reuters: "We control most of Sabha apart from the al-Manshiya district. This is still resisting, but it will fall."
Mohammed Wardugu, of the Desert Shield Brigade that is fighting in the area, went further, telling Agence France-Presse the city was "totally under the control of the revolutionaries".
The NTC had said on Monday that its forces had captured the airport and a leading garrison in Sabha, taking 150 prisoners from the Gaddafi forces.Sabha has a large sub-Saharan element in its 100,000 population and many are thought to fear reprisals, given the number of mercenaries employed by Col Gaddafi.
The city has been part of the escape route south - a number of convoys carrying Gaddafi officials have travelled through it to Niger - and anti-Gaddafi forces want to seal it off.
Fierce fighting continues at the coastal town of Sirte, where anti-Gaddafi forces have suffered significant losses.
Nearly 50 fighters have died and more than 200 have been injured, doctors say, since the NTC moved on Col Gaddafi's home town on 15 September.
NTC spokesman Zuber al-Gadir admitted to AFP that "the majority of residents are with Gaddafi" in Sirte because of the former regime's propaganda machine.
Anti-Gaddafi forces are also still engaged in trying to eliminate pockets of resistance outside Sirte.
Meanwhile, the NTC is continuing to gather diplomatic support.
Interim Prime Minister Mahmoud Jibril is at the UN General Assembly meeting in New York.
He said he expected a new government to be announced within 10 days.
The African Union has now said it is ready to support the NTC.