Forces of Libya's new regime were on the verge of claiming full control of Muammar Gaddafi's hometown Sirte after seizing its showpiece conference centre and university from his diehards on Sunday.

The fortress-like Ouagadougou conference centre, constructed to host pan-African summits, has been a major objective of the National Transitional Council forces since they launched an offensive to take the city on September 15.

"We control 100 percent of the Ouagadougou centre," said Mohammed al-Fayad, an NTC military leader, adding the capture of the complex "opens the way" for his forces to overrun the city centre.

An AFP correspondent on the spot confirmed the NTC fighters were in control of the vast complex.

"We are ready to take the centre" of Sirte "within a matter of hours," said Fayad.

"It is only a question of coordination between (Misrata fighters on) the western front and (Benghazi fighters on) the eastern front. We just need time," he told AFP.

As he spoke, NTC fighters spread throughout the sprawling complex, taking down portraits of the fugitive Gaddafi and the green flags of his fallen 42-year regime.

But they were soon sent scurrying for cover as the din of armed clashes heard in the distance grew louder and nearer in the streets surrounding the conference centre.

A day after taking a four-lane avenue into the centre, the NTC forces also took control of Sirte's university and its new campus, a huge site where Kadhafi snipers had been picking them off from unfinished buildings.

"We have taken the university... we have liberated the area from Kadhafi's dogs," NTC commander Nasser Zamud said, as hundreds of his fighters roamed the campus.

"The fighting has been difficult; there were a lot of snipers," Zamud said of the assault on the university in the Mediterranean city's southeast.

Their gains in the battle for Gaddafi's birthplace have come at a heavy cost, however.

And the ferocity of the Gaddafi forces' resistance in Sirte and their other main bastion, Bani Walid, has surprised the new regime, with NTC chief Mustafa Abdel Jalil admitting the battle was 'very vicious.'

"Our fighters today still have to deal with snipers in high positions," he told a joint news conference in Tripoli late Saturday with visiting British Defence Secretary Liam Fox and Italian counterpart Ignazio La Russa.

Medics said six NTC fighters were killed and 99 wounded on Saturday, taking the toll to 23 dead and almost 330 wounded since they launched what they are calling their final assault on the Gaddafi bastion.

There were no immediate figures for any casualties on Sunday. Thousands of civilians are still trapped in Sirte, and NTC commanders said they have been pacing their advance to evacuate some of those who had not fled and to avoid losses from friendly fire.

One resident, Nasser Hamid, who was fleeing with his wife, three children and niece, said his family managed sneak out in their loaded car under the cover of dark early on Sunday.

"Our flat was destroyed by machinegun fire. We stayed in the stairwell. The children were upset because their toys were destroyed," Hamid told AFP.

"We waited so long because the Gaddafi loyalists said if we left, they would never let us come back."

His wife Salima Ali Omar said however that the forces loyal to the old regime appeared to be fighting a losing battle.

"The (Gaddafi) volunteers say they are fed up, they don't want to fight any more. They are throwing their guns in the rubbish bins," she said.

On the western front, the NTC forces were also in control of most of the so-called 700-house complex, but they came under sniper fire as they advanced on Sunday, another AFP correspondent reported.

"We're waiting for reinforcements to come and then we will move forward," NTC commander Ahmed Brasali said from a frontline position.

"We were attacked this morning by 10 Gaddafi loyalists on foot; they fired RPGs and Kalashnikovs. We killed them all," he told AFP.

The gains inside Sirte are seen as crucial by the NTC, which is awaiting the city's capture to declare the liberation of the whole of Libya, clearing the way to draw up a timetable for elections.

The council has ruled most of the oil-rich country since its forces overran Tripoli on August 23, forcing Kadhafi and his inner circle on the run.

NTC commanders believe that one of Gaddafi's sons, Mutassim, is holed up in Sirte and that another, Seif al-Islam, once seen as the former strongman's successor, is hiding in Bani Walid, possibly with his father.

New regime fighters have been stationed for weeks outside Bani Walid, a Saharan oasis 170 kilometres (100 miles) southeast of Tripoli, and the frustration is beginning to show.

"I want to fight but I am awaiting orders," said a young man at a mosque some 40 kilometres (25 miles) north of Bani Walid which serves as a base for the NTC forces.

Field commander Yusef al-Sharif insists that the campaign for Bani Walid is progressing.

"Gaddafi's men have left Bani Walid, they are fighting 10 kilometres (six miles) from the city centre," he said.

"We control 90 percent of the sector. We just have to push the pro-Gaddafi guys out of the outskirts and tackle the snipers."