Azerbaijan , Baku, Sept. 21 / Trend A. Isgandarov /
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, BBC reported.
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 Tuesday that its forces had captured the airport and a leading garrison in Sabha, taking 150 prisoners from the Gaddafi forces.
Mass demonstrations demanding for the ouster of Qaddafi, who has been ruling the country for more than 40 years, started in Libya in mid-February and subsequently grew into armed confrontation between the government forces and the rebels