Muammar Gaddafi claimed this morning to have gone on a Tripoli walkabout incognito, and no one recognised him.

It was his second audio message after his compound was overrun by rebels yesterday afternoon.

The hunt for the former leader intensified through the morning after Gaddafi said his decision to leave the compound was a 'tactical withdrawal'.

Two powerful blasts thought to be caused by an air attack rocked the capital early in the morning as a NATO warplane flew overhead. Heavy firing could be heard around the Rixos Hotel, where 30 journalists have been holed up for days. They said this was rapidily evolving into a hostage situation. 

Rebel fighters said they had found no trace of Gaddafi when they swarmed through his compound yesterday, raiding his armoury, raising their flag and ripping the head off a statue of the strongman.

"Bab al-Azizya is fully under our control now. Colonel Gaddafi and his sons were not there; there is nobody," said military spokesman Colonel Ahmed Bani "No one knows where they are."

Wherever he may indeed be, the strongman is still managing to get his messages out.

In a speech carried early this morning by the website of a television station headed by his son Seif al-Islam, Gaddafi said he had abandoned his compound in a "tactical withdrawal" after it had been wrecked by NATO warplanes.

"Bab al-Azizya was nothing but a heap of rubble after it was the target of 64 NATO missiles and we withdrew from it for tactical reasons," he said.

The speech gave no indication of where he had gone.

In a later audio message on Syria-based Arrai Oruba television station, Gaddafi boasted that he had taken to the streets of Tripoli without being recognised.

"I walked incognito, without anyone seeing me, and I saw youths ready to defend their city," the strongman said, without specifying when he did his walkabout.

He also urged "the residents, the tribes, the elderly to go into the streets... and cleanse Tripoli of rats" -- referring to the rebels.

Gaddafi spokesman Mussa Ibrahim claimed to the Arrai Oruba channel that more than 6,500 "volunteers" had arrived in Tripoli to fight for the regime, and called for more.

Insurgents, jumpy but jubilant and armed with assault rifles, combed the streets of the capital for remnants of the regime.

"We are the champions. We've been dying for 42 years and now we are going to live," said Sharif Sohail, a 34-year-old dentist who took up arms to patrol the city centre.

Other rebel fighters, some wrapped in Free Libya flags, some wearing flackjackets, manned checkpoints through the night, scrutinising traffic by flashlight in neighbourhoods without electricity.

"We are checking every car that passes," Brahim Mukhtar, 27, told AFP at a main intersection near Souk al-Fatah. "We are guarding the streets."

Opposition leader Mustafa Abdel Jalil pledged that Libya will hold elections in eight months and was adamant that Gaddafi will be tried in the country.

"In eight months we will hold legislative and presidential elections. We want a democratic government and a just constitution," promised Abdel Jalil, chairman of the rebel National Transitional Council (NTC)

"Above all we do not wish to continue to be isolated in the world as we have been up to now," he added in comments published in the Italian La Repubblica daily.

Residents of the capital had celebrated late into the night following the capture of the Bab al-Azizya compound.

But in the early hours of Wednesday, the streets grew eerily empty of residents while rebels and loyalists engaged in deadly cat-and-mouse warfare and fears of Gaddafi snipers on rooftops dampened the jubilation.

The attack on Gaddafi's headquarters followed three days of fighting in the capital which Abdel Jalil said had left more than 400 killed and 2,000 wounded.

He did not specify if he was talking of both sides.

In an interview with France 24 television, Abdel Jalil also said that some 600 pro-Gaddafi fighters had been captured but the battle would not be over until the Libyan leader himself was a prisoner.

He said three areas of the capital were still resisting, including Abu Slim, from where half-a-dozen mortar bombs fell on Bab al-Azizya late Tuesday.

Rebels said Gaddafi loyalists in his birthplace of Sirte, the last major regime bastion remaining, had fired a missile at rebel-held Misrata, hours after negotiations began to try to secure a surrender of the city.

On the eastern front, Libyan rebels yesterday overran the eastern oil hub of Ras Lanuf on the road to Sirte, spokesman Bani said.

In Doha, NTC number two, Mahmud Jibril said Libya's transition "begins immediately" and that Qatar would host a meeting today to organise $2.4 billion in aid for the country.