Libya's new rulers on Thursday stepped up the hunt for Moamer Kadhafi's inner circle, seeking the arrest of one of his sons, Saadi, amid conflicting reports of the capture of his spokesman Mussa Ibrahim.
They also said another Kadhafi son, Mutassim, was in the deposed despot's birthplace of Sirte, where old regime loyalists fought pitched battles with combatants loyal to the ruling National Transitional Council.
Meanwhile, interim prime minister Mahmud Jibril said he will not be a part of the new government, the formation of which has been postponed until the end of the country's conflict.
"Misrata fighters contacted us and gave us the information that Mussa Ibrahim has been captured," said Mustafa bin Dardef, of the NTC's Zintan Brigade.
Another commander, Mohammed al-Marimi, said: "Mussa Ibrahim was captured while driving outside Sirte by fighters from Misrata."
He said there were reports that Ibrahim was dressed as a woman, but could not immediately confirm that.
Libya's Al-Hurra Misrata television also said Ibrahim had been caught outside Sirte and that he had been in a car and veiled, adding that it would soon broadcast footage of his capture.
However, late Thursday, a spokesman for the Misrata military council Adel Ibrahim told AFP, "We cannot confirm he was arrested."
Mussa Ibrahim was the public voice of the Kadhafi regime.
Since NTC fighters overran Tripoli on August 23, he has continued to issue statements through Syrian-based Arrai television from an unknown location, although not so frequently in recent days.
On Friday, he appealed for resolve against "agents and traitors," denounced what he called "genocide" by NATO and its "Libyan agents" and criticised the world community for "inaction."
Global police agency Interpol said, meanwhile, the NTC had requested an arrest notice against Saadi Kadhafi, who is believed to be in Niger.
It said the Libyan authorities wanted him "for allegedly misappropriating properties through force and armed intimidation when he headed the Libyan Football Federation."
Saadi, 38, was last seen in Niger and the red notice calls particularly on countries in the region to help locate and arrest him "with a view to returning him to Libya where an arrest warrant for him has been issued," Interpol said.
Niger's Prime Minister Brigi Rafini said later Thursday that his country had no plans to send Saadi home to face justice.
"Saadi Kadhafi is in safety, in security in Niamey, in the hands of the Niger government. There's no question of him being extradited to Libya for the moment," Rafini told AFP on a visit to France.
"We need to be sure he will be allowed a fair defence," he said. "Are those conditions in place today? No."
While the fugitive Kadhafi's whereabouts remain unknown, Libya's defence ministry spokesman Ahmed Bani has said that his most prominent son, Seif al-Islam, was in Bani Walid and that Mutassim was in Sirte.
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An NTC field commander in Sirte also told AFP that Mutassim was in the Mediterranean city, which lies some 360 kilometres (225 miles) east of Tripoli.
"Mutassim is inside and he is commanding his forces. They are using heavy guns as well as snipers, which is making it difficult for us."
Along with his father and former intelligence chief Abdullah al-Senussi, Seif is wanted by the International Criminal Court for alleged crimes against humanity.
On the front in Sirte, meanwhile, anti-Kadhafi fighters returned to the fray after being forced to retreat during ferocious fighting on the eastern edge of the Mediterranean city that had raged through the night.
An AFP correspondent said the two sides shelled each other and traded heavy machine-gun fire around the port as well as near the Mahari Hotel.
The firefight intensified, with NTC tanks firing barrage after barrage of shells at loyalist positions and pro-Kadhafi snipers firing on the NTC fighters from rooftops, the reporter said.
NTC military chiefs said their forces remained in control of the hotel and the port, which they overran on Tuesday, but that the situation was fluid.
"The battle is fierce," said one field commander, who asked not to be identified.
"It is not going to be easy to capture Sirte. We thought we would be inside Sirte this Friday, but now I think it will not happen," he told AFP.
"The Misrata Military Council and our representatives will meet later today to discuss the next strategy for capturing Sirte," the NTC commander bin Dardef told AFP.
Meanwhile, residents of Sirte, caught in the crossfire and suffering without electricity, water and adequate food supplies, continued to flee the city.
NTC officials at a checkpoint 50 kilometres west of the city said another 500 people had registered on Thursday and that six suspected Kadhafi loyalists were among those in the crowd.
An AFP correspondent saw NTC fighters searching one car, in which they found a bag full of bullets, a hand grenade and a Kadhafi uniform.
The NTC said they catch about 10 Kadhafi loyalists a day.
Equally fierce resistance from loyalists in the desert town of Bani Walid, Kadhafi's other remaining bastion, has stalled a final assault by NTC fighters, said commanders, who urged NATO to increase its air support.
An AFP correspondent said that despite using tanks, rocket launchers and artillery, the NTC forces had not advanced from positions held for the past few days in Bani Walid, 170 kilometres southeast of Tripoli.
On the political front, Jibril was asked at a news conference in Tripoli about the timetable for the government's announcement.
"I hope that soon we will free Sirte and Bani Walid to begin negotiations on the formation of the transitional government, of which I will not be a part."
Jibril, known for his liberal leanings, heads the NTC's executive office and faces opposition from Islamists within the body.
He said the office will continue its work until the "total liberation" of Libya.