Libyan fighters have made major progress into Sirte, the home city of toppled leader Muammar Gaddafi.
National Transitional Council (NTC) forces said on Sunday they had managed to take control of Al Giza district, where a large number of pro-Gaddafi forces were based, as well as the city's university, and Ibn Sina hospital.
Some 15 Gaddafi loyalists were captured from the hospital, a witness told the Reuters news agency.
Despite stiff resistance from Gaddafi loyalists, NTC fighters also captured the Ouagadougou conference centre, which is believed to have housed the command centre of Gaddafi's forces and was protected by a large number of snipers.
Al Jazeera's Tony Birtley, reporting from Sirte, said: "They have taken the Ouagadougou conference centre, the university, and the hospital. But there has been intense fighting for a third day.
"The NTC fighters now say they have something like 70 per cent of Sirte under their control. But the remaining 30 per cent poses a problem, because it is going to entail street fighting.
"Gaddafi's fighters, who are said to number about 2,000, are putting up a tough resistance. We are in a situation where NATO can't help. They are up close and personal, fighting street by street."
The NTC fighters also launched a major offensive on Bani Walid, another town southeast of the capital Tripoli still controlled by Gaddafi forces.
According to an Al Jazeera correspondent near the desert town, NTC forces have reached the first mosque on the outskirts of Bani Walid.
Abdullah Khansheel of the Bani Walid military council said NTC fighters were also in control of the airport, approximately 75km from the city centre.
'Liberation in days'
Mustafa Abdul Jalil, chairman of the National Transitional Council, said both Sirte and Bani Walid would be liberated within days.
"I will reassure all Libyans that the liberation will be done in the coming few days. The city of Bani Walid is
under siege from five directions," Jalil told reporters.
"As for Sirte, after the heavy fighting yesterday and the day before, the fighters reached the city centre and
they are combing the residential neighbourhoods where there are some snipers. I think and I hope with the help of God the liberation of these two towns will be completed by the end of this week," he added.
The fight to seize control of the Ouagadougou centre proved particularly tough with Gaddafi loyalists entrenched in concrete bunkers.
"It has been hit for days by tank guns and rockets, but it hasn't budged. Its paint has hardly been scratched," one NTC fighter said.
Abdel-Basit Haroun, an NTC field commander, said 32 people had been killed in Sirte since anti-Gaddafi fighters began the "final push" operation on Friday. Hundreds more were reported wounded.
It is unclear how many civilians are still inside the city. Thousands of residents have fled since the standoff began three weeks ago.
International organisations allowed into the embattled town last week to visit the hospitals said conditions were "dire", with patients sitting in corridors of buildings that got shelled.