Fresh fighting erupted in Tripoli on Tuesday hours after Moammar Gadhafi's son turned up free to thwart Libyan rebel claims he had been captured, a move that seems to have energized forces still loyal to the embattled regime.
Rebels and pro-regime troops fought fierce street battles in several parts of the city, a day after opposition fighters swept into the capital with relative ease, claiming to have most of it under their control.
Thick clouds of gray and white smoke filled the Tripoli sky as heavy gunfire and explosions shook several districts of the city of 2 million people. Some of the heaviest fighting was around Gadhafi's Bab al-Aziziya main compound and military barracks.
The compound, which has been heavily damaged by NATO airstrikes, has emerged as one of the centers of government resistance since tanks rolled out Monday and began firing at rebels trying to get in.
Seif al-Islam's sudden - even surreal - arrival at a Tripoli hotel where foreign journalists are staying threw the situation in the capital into confusion. The appearance of Gadhafi's son and former heir apparent underlined the potential for the longtime Libyan leader, whose whereabouts remain unknown, to strike back even as his grip on power seemed to be slipping fast.