Libya conflict: Gaddafi town Sirte 'close to falling'
Interim government forces in Libya have made significant gains in the battle for the city of Sirte - hometown of the fugitive leader Col Muammar Gaddafi.
National Transitional Council (NTC) commanders said they had captured the main hospital, the university and the Ouagadougou conference centre.
But heavy street fighting continues around Sirte city centre.
Once Sirte falls, the NTC say they will declare national liberation, even if Col Gaddafi remains at large.
Pro-Gaddafi forces also control the desert enclave of Bani Walid, but it is seen as less significant as it does not lead to any exit routes from the country.
In August, members of Col Gaddafi's family and his inner circle fled to neighbouring Algeria and Niger.
"I do believe, God willing, that the liberation of these cities [Sirte and Bani Walid] will happen within this week," NTC chairman Mustafa Abdul Jalil told reporters in Tripoli.
Gaddafi loyalists made a bastion out of the sprawling Ouagadougou conference centre, built to host pan-African summits.
Snipers stationed on the roof picked off NTC fighters as they approached.
But by Sunday afternoon, NTC fighters said they had taken control of the badly damaged complex.
They also captured the main Ibn Sina hospital in Sirte, where scores of people wounded in the offensive were seeking treatment. While many were civilians, others were taken into custody by the NTC, suspected of being Gaddafi loyalists.
Revolutionary fighters roamed the corridors, checking identification papers and searching the beds of those believed to be disguising themselves.
The Associated Press says the wounded were lying on gurneys and floors to protect themselves from the firing going on outside.
"We took 50 prisoners. They were mostly mercenaries. They were lying in beds pretending to be wounded. Some were wounded. We found Kalashnikov and other weapons under their beds," Osama Swehli Muttawa, an NTC field commander, told AFP.
The hospital has no electricity or water, and a handful of medical students and nurses were the only medical staff, AP reports.
The NTC believed one of Col Gaddafi's sons was hiding in the hospital, but there has so far been no sign of him or word of his whereabouts.
The BBC's Wyre Davies, in Sirte, says NTC forces suffered heavy losses after pro-Gaddafi fighters unleashed a mortar barrage on them.
Our correspondent says he saw dozens of dead and wounded NTC troops at a field hospital outside the city.
Thousands of civilians are said to remain trapped in Sirte, many of them fearful of retaliation by NTC forces.
The NTC have also captured one of Col Gaddafi's lavish residences in Sirte. Photographs showed the former rebels standing on a four-poster bed as they searched a room in the palace, built by the colonel during his 42 years in power.
NTC fighters came up against heavy weapons including tanks and artillery in Sirte on Friday and Saturday.
An NTC commander, Nasser Zamud, told AFP the fighting in the university area had been "difficult" with NTC forces facing "a lot of snipers".
Video showed one injured fighter at the campus hobbling after his comrades with a crutch in one hand and a Kalashnikov assault rifle in the other.
On Friday, NTC forces launched what they called a final assault on Sirte, pushing pro-Gaddafi fighters back from their positions and towards the city centre.
But on Saturday, their rapid advance slowed down as they fought street by street to take control of the city, Libya's symbolic second capital under Col Gaddafi.
By the end of the day, they had taken control of a key boulevard which connects the Ouagadougou centre to the city centre.
Civilians continued to leave Sirte on foot and by car over the weekend. NTC forces stopped and searched them at checkpoints.
On Thursday, Col Gaddafi delivered an audio message urging Libyans to take to the streets "in their millions" to resist the interim leaders.