Forces loyal to Libya's interim government pounded Moamer Kadhafi's diehards in Sirte on Saturday as they resumed their battle for full control of the ousted despot's birthplace.
A senior US defence official said, meanwhile, that NATO chiefs believe the fugitive former Libyan leader no longer commands his loyalists, who are on the verge of defeat.
A day after launching what they said is a final assault on Sirte, the forces loyal to the ruling National Transitional Council unleashed a barrage of rocket-propelled grenades and anti-aircraft gunfire.
The fighting centred on Sirte's Ouagadougou conference centre and nearby university, where holed-up Kadhafi loyalists have been responding with only sporadic mortar and small arms fire.
And after launching what they called a final assault on Sirte with a barrage of rocket and artillery fire, the NTC forces still faced stiff resistance late on Friday.
"We are surrounding them in the centre of the city in an area of just a few square kilometres (miles)," NTC commander Nasser Abu Zian told AFP.
An AFP correspondent said the NTC forces resumed the assault on Saturday after a sandstorm eased, boosting visibility in and around Sirte, once a symbol of Kadhafi's regime.
Civilians trickled out on foot, including a woman who carried a child in her arms and a man lugging suitcases, as NTC forces stopped cars for identity checks and searches.
"We just want to go somewhere that is safe. I hadn't been out of my house for three weeks because of all the firing. Lots of houses in my area were hit," said Sudanese labourer Abdulrahim Kabash.
Milad Gahnatri, whom the NTC forces suspected was Mauritanian, appealed to be let through to seek medical treatment for two pale-looking men in the back of his car.
"These are my brothers. They need kidney dialysis three times a week but the Ibn Sina hospital is damaged by bombing. There are many patients in there and they are all afraid of the firing from all sides," he said.
In eastern Sirte, NTC fighters overlooking the rectangular 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," said one of them with a Kalashnikov.
The number of NTC fighters at the front was lower than on Friday, when hundreds poured into Sirte at dawn on heavily armed pick-ups, following a ferocious artillery and rocket barrage.
In Friday's offensive, the NTC fighters came under sustained mortar, machinegun and sniper fire but took a 700-home complex west of the centre, they said.
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Plumes of black smoke billowed from several parts of the city as the Ouagadougou centre was constantly shelled by 106 mm cannon and anti-aircraft guns.
NATO warplanes flew overhead, and the alliance said in its latest operational update that the only target it struck across the country on Friday was a firing on a vehicle staging point in Sirte.
At least 12 NTC fighters were killed and 193 wounded, the military said, but there were no immediate casualty figures from the eastern side of the Mediterranean city, 360 kilometres (225 miles) east of Tripoli.
Late Friday, interim defence minister Jalal al-Digheily said the end of the conflict was near.
"We are very close to the end of the war and peace will be restored all over Libya," he told reporters in Tripoli on the occasion of visits by his British and Italian counterparts, Liam Fox and Ignazio La Russa.
"There are still some hot spots but they won't resist very long," he added of Sirte and Bani Walid, a desert oasis 170 kilometres (100 miles) southeast of the Libyan capital.
Sirte and Bani Walid are Kadhafi's last major bastions against the NTC, which has ruled most of the oil-rich country since its forces overran Tripoli on August 23.
Kadhafi has since gone into hiding.
On Thursday night, the elusive former strongman called "on the Libyan people, men and women, to go out into the squares and the streets and in all the cities in their millions" to reject the NTC.
"I say to them, do not fear anyone. You are the people, you belong to this land," he said in an audio message broadcast on Syria-based Arrai television.
However, a senior US defence official said NATO chiefs believe Kadhafi no longer commands forces loyal to him and his supporters are on the verge of defeat in Sirte.
"He (Kadhafi) effectively doesn't exercise command and control over militias loyal to him," the official said on condition of anonymity.
An NTC commander outside Bani Walid told AFP on Friday a new mediation attempt was underway, but if it failed a fresh assault would be launched there.
"To avoid a bloodbath," Omar Fifao said a delegation had been sent to negotiate with tribes in Bani Walid, some of whose number are fighting alongside Kadhafi forces.
"We have asked for a meeting so we can enter Bani Walid without fighting, but if no deal is reached we will have no option but to attack," Fifao said.
NTC commanders have said Kadhafi's most prominent son, Seif al-Islam, is in Bani Walid and possibly Kadhafi as well.