Report from the advance on Tripoli

What happens next remains to be seen.

UPDATE 11:54 PM

Here's a report and video from Sky News which has a reporter embedded with the rebels: Sky's special correspondent Alex Crawford, accompanying the rebels, said the opposition fighters were greeted with scenes of jubilation as they made their way through the outskirts of the capital.

As they entered the city, their cars gridlocked the roads, she said, and hundreds of people came out onto the streets to greet them.

The rebels responded with celebratory gunfire, she said.

"We are now just a very short distance from the centre, with more and more people coming onto the streets.

"They (the rebels) had been expecting much more resistance but there has been very little."

"There is absolutely no question in their minds that they have beaten Gaddafi and it is just a question of how he will go," she added.

The quick advance came after the fighters captured the base of the Khamis Brigade, 16 miles west of the capital.

It is said to be one of the best-trained and equipped units in the Libyan military and is commanded by Col Gaddafi's 27-year-old son Khamis.

Aside from the main rebel movement from the west of the city, fighting also broke out in the city's Mitiga airbase, while the suburb of Tajoura reportedly also fell under rebel control.

Gunfire was also heard near the hotel where foreign media are staying.

As the rebel movement came closer to the capital, Col Gaddafi broadcast a message on state television calling on Libyan people to come from all regions and liberate Tripoli.

He said he was "afraid Tripoli will burn" but that he will remain in the city until the end.

The Libyan government also earlier appealed for an immediate ceasefire and an end to Nato's "aggression".

Spokesman for Colonel Muammar Gaddafi's regime, Moussa Ibrahim, told reporters the rebels were nothing without Nato and they would never be able to take Libya. Maybe. But Gadhafi is now gone.

Let's go to the videotape.