Libyan government forces said on Tuesday they believed they had one of Muammar Gaddafi's sons cornered in the centre of the deposed leader's home town, but determined resistance was keeping them at bay.
After weeks of fighting, forces of the National Transitional Council (NTC) have taken most of Sirte and driven Gaddafi loyalists into two neighbourhoods in the north of the city.
Capturing the city, which Gaddafi had turned into a showcase second capital, will consolidate the NTC's control in Libya and allow it to focus on rebuilding the country, but international concern about civilians caught up in the fighting has mounted.
One NTC commander said Gaddafi fighters were defending their last two districts in Sirte tenaciously because Mo'tassim Gaddafi, his father's national security adviser, was with them.
"There are a few (Gaddafi-held) pockets, mainly concentrated in the 'Dollar' neighbourhood," said Colonel Mohammed Ajhseer. "According to the information we have, this is where Mo'tassim is, with another group."
As the fighting raged in the streets, terrified families were emerging from their houses and trying to leave.
NTC fighters surrounded their vehicles and searched them for weapons—a mark of the deep mistrust in Sirte where many people belong to Gaddafi's tribe and opposed his overthrow.
"There are explosions all the time," said one woman, who was in a white van with seven children. "There is no water. There is nothing," she said, then started crying.
One man said he and his family had tried to leave the city twice before but had to turn back because they had no fuel for their car and the fighting was too heavy.
"We didn't know how to sleep because of the explosions. We couldn't even leave the house. There is no food. We just had flour and salt and bread," he said, as his wife, who was weeping, sat in their vehicle with their three children.
On the western outskirts of Sirte, a flat-bed truck drove out carrying about 30 people, including children clutching dolls and blankets. It was raining, and they were wet and shivering.
They said they originally came from Morocco and Sudan, and had been trapped in Sirte because Gaddafi militias would not let them leave.
One of them, Abdul Menem Ahmed, from Ondurman in Sudan, said he had been working as an accountant in Libya for 14 years.
"The Gaddafi militias say everything is fine, then about 10 minutes later the shelling starts. There is no food no water, no medicine," he said.
Muammar Gaddafi himself is not in Sirte, according to NTC officials coordinating the hunt for him, but is instead believed to be far to the south in the Sahara desert.
Sirte, once a fishing village, has symbolic significance because Gaddafi used it as a prop in the personality cult he built during his 42 year rule. He built opulent villas, hotels and conference halls there to host Arab and African leaders.
With Libya's new rulers focused on the bruising battles for Sirte and Bani Walid, another pro-Gaddafi town, a political vacuum has emerged. There is no formal government and the process of holding elections is on hold.
Armed anti-Gaddafi factions from different regions are vying for power, complicating the NTC's task of asserting national control in the oil-exporting nation of six million people.
NTC forces have captured Sirte's most important landmarks, including the Ouagadougou conference hall, where Gaddafi once hosted lavish summit meetings, the hospital and the university.
Local commanders say Gaddafi loyalists are holed up in a neighbourhood known as "Dollar" and another called al-Shabiya, their forces weakened after nearly two months under siege and near-constant bombardment by NATO-backed NTC forces.
"(I have seen) a lot of Gaddafi fighters dead and injured in the past few days," said Karim Hassan, a migrant worker from Morocco who fled the city on Tuesday.
But the loyalists are defending their positions and even mounting counter-attacks. A Reuters reporter in the centre of Sirte said a pick-up truck that was behind NTC lines was burned out after it was hit by a rocket-propelled grenade (RPG).
One NTC fighter, Ali al-Rujaiy, said the loyalists wait until their opponents are gathered in one place, then strike. "They hit us with RPGs and mortars. They ambush us," he said.
On a hilltop further south, several hundred NTC fighters were massing for a fresh offensive on the pro-Gaddafi holdouts, battering them first with tank and artillery fire.