Gaddafi appeared on TV as the popular uprising against him spread to Tripoli, assumed to be his last stronghold.
Latest reports say the main road between the military airport and the city centre is lined with police and troops who are searching vehicles.
Several people are reported to have been shot dead as the revolt headed closer to the heart of the city.
Video posted on the internet appeared to capture the sound of heavy gunfire.
The anti-Gaddafi movement has been closing in on Tripoli for more than 24-hours. Key cities around the capital like Zawiyah and Misrata are now reported to be free of government forces.
Residents in Benghazi celebrated Friday prayers for the first time since the country’s second city broke away from Gaddafi’s regime.
It is in the east of Libya which was the first to be taken over by the rebels, helped in no small part by significant defections from the Libyan military.