Libyan fighters are continuing their push to capture Sirte, the home city of toppled leader Muammar Gaddafi.
National Transitional Council (NTC) forces said they had managed to take control of a central neighbourhood and Sirte university on Sunday, but faced stiff resistance from Gaddafi loyalists.
Fighting was raging for the Ouagadougou conference centre on Sunday, which is believed to house the command centre of Gaddafi's forces, Al Jazeera's Zeina Khodr reported from the outskirts of the city.
"They (NTC) are making further gains into Sirte," Khodr said.
"Loyalists are not only using small arms fire and snipers to slow the advance, they're also firing mortars to prevent anti-Gaddafi forces from taking control of this strategic complex," she said.
But NTC fighters made progress elsewhere, capturing the nearby Sabamiyah neighbourhood.
"Most of the people living here were commanders and officers in Gaddafi's army," Khodr said.
"You can see green flags hoisted on top of the villas, and when you go inside the homes, you'll see posters of Gaddafi and army certificates".
The fighters also wrested control of the four-lane avenue that links the centre of the city to the Ouagadougou conference complex, the AFP news agency reported.
NTC forces bombarded the city with artillery shells fired from hundreds of vehicles carrying rocket launchers.
Fighters overlooking the Ouagadougou centre said its concrete bunkers were proving tougher than they originally thought.
"It has been hit for days by tank guns and rockets, but it hasn't budged. Its paint has hardly been scratched," one of them said.
Abdel-Basit Haroun, an NTC field commander, said 32 people had been killed since anti-Gaddafi fighters began the "final push" operation on Friday. Hundreds more were reported wounded.
Poor visibility caused by a sandstorm on Saturday delayed the prospect of ending a three-week standoff, during which thousands of residents have fled from the coastal city.
Our correspondent spotted a few families managing to escape on Saturday, but she said it was difficult to tell how many more civilians were trapped inside the city as a result of the fighting.
Sirte residents who oppose Gaddafi said his loyalists were preventing residents from leaving the town despite the lack of food, water and electricity.
International organisations allowed into the embattled town to visit the hospitals said conditions were "dire", with patients sitting in corridors of buildings that got shelled.
NATO operations 'to continue'
Mustafa Abdul-Jalil, the head of the NTC, called on the international community to help treat the wounded in Sirte, saying they could deduct the cost from Libyan assets that were frozen under Gaddafi's regime.
He held a news conference in the capital, Tripoli, with Liam Fox and Ignazio La Russa, the defence ministers of the UK and Italy respectively, the latest in a string of foreign dignitaries to visit the country.
Liam Fox pledged to keep up NATO airstrikes even after Sirte's fall, saying the international military action would continue as long as the remnants of the Gaddafi regime posed a risk to the people of Libya.
"We have a message for those who are still fighting for Gaddafi that the game is over, you have been rejected by the people of Libya,'' he said.
Gaddafi forces remain entrenched in the central city of Bani Walid, but transitional leaders say they will declare "liberation" without it because Sirte's fall will give them control over all seaports and harbours.
Officials with the new government, which has ruled most of the country since its forces overran Tripoli on August 23, say Gaddafi is probably being sheltered by nomadic Tuareg tribesman far to the south, in the Sahara desert.
Some NTC officials said his son Motassim, who used to be the national security adviser, was hiding somewhere in Sirte. Gaddafi's most prominent son, Saif al-Islam, is rumoured to be in Bani Walid.