A man waves the Libyan rebel flag during a celebration in the town of Maia after fighters pushed pro-Gaddafi government forces back to within 25 km of Tripoli, August 21, 2011. ( Image: REUTERS/Bob Strong )
A convoy of rebels entered a western neighbourhood of the city, firing their weapons into the air. Rebels said the whole of the city was under their control except Gaddafi's Bab Al-Aziziya-Jazeera stronghold, according to Al-Jazeera Television.
Gaddafi made two audio addresses over state television calling on Libyans to fight off the rebels.
After a six-month civil war, the fall of Tripoli came quickly, with a carefully orchestrated uprising launched on Saturday night to coincide with the advance of rebel troops on three fronts.
Rebel National Transitional Council Coordinator Adel Dabbechi confirmed that Gaddafi's younger son Saif Al-Islam had been captured. His eldest son Mohammed Al-Gaddafi had surrendered to rebel forces, he told Reuters.
Al-Jazeera television aired images of people celebrating in central Tripoli and tearing down posters of Gaddafi, which had dominated Libyan cities for decades.
In Benghazi in the east, thousands gathered in a city centre square waving red, black and green opposition flag as news filtered through of rebel advances into Tripoli.