Libya's state TV has shown footage of Col Muammar Gaddafi meeting tribal leaders in Tripoli - his first public appearance in nearly two weeks.
Libyan officials said the video was shot in the capital on Wednesday. This has not been independently verified.
Col Gaddafi has not been seen since 30 April - when a Nato strike killed his youngest son and three grandchildren.
Earlier, Libyan rebels said they had seized Misrata airport in the west, driving back pro-Gaddafi troops.
Government forces have been pounding the western city, which remains largely under rebel control, for weeks.
Meanwhile, fresh explosions were reported in Tripoli on Wednesday.
Nato said earlier that its planes had carried out 6,000 missions over Libya since it assumed command of military operations there at the end of March.
The air strikes have helped secure rebels in their strongholds in eastern Libya, but observers say it remains unclear to what extent they have loosened Col Gaddafi's grip on the west of the country.
In the footage, Col Gaddafi was dressed in his trademark brown robes, dark sunglasses and black hat. He appeared to be in good health.
"We tell the world, 'those are the representatives of the Libyan tribes,'" Col Gaddafi said, pointing to his visitors.
A man then was seen telling him: "You will be victorious."
On Wednesday, eyewitnesses said Misrata airport fell after hours of fighting between rebels and pro-Gaddafi forces.
The bodies of pro-government forces could be seen lying in the street as the rebels celebrated their victory, correspondents said. A dozen rebels were said to have been wounded in the fighting.
Col Ahmed Bani, a spokesmen for the rebel leadership in the eastern rebel stronghold of Benghazi, told the BBC that as well as taking the airport, "revolutionary forces" now controlled Misrata.
As well as burning government tanks, the rebels had captured other weaponry from the regime troops, he said.
Libya's third-largest city, Misrata is the only significant western rebel holdout and is strategically important because of its deep-sea port, which has become a lifeline for supplying civilians and for evacuating wounded people fleeing the fighting.
Though the rebels are said to be better organised than those in eastern Libya and have, for example, set up a network of makeshift arms factories, their campaign is still widely seen as an improvised affair.
Following a wave of revolutions across the region, Libya's uprising was sparked by February's arrest of a human rights campaigner in Benghazi, and rapidly spread to other cities.
Authorities used aircraft to attack protesters, prompting the resignation of many Libyan diplomats as rebel forces called on Col Gaddafi to relinquish his five-decade rule and open Libya up to a more democratic rule.
The EU has frozen the assets of Col Gaddafi and members of his family, and banned the supply of arms, ammunition and any equipment that could be used for "internal repression".