Residents said on Thursday there has also been a wave of anti-government protests in several Tripoli neighbourhoods this week - dissent that in the past has been met with zero tolerance and brutal force.
Gaddafi's rebel opposition, meanwhile, received major political boosts from abroad. Britain promised to provide them with police gear, and the Obama administration invited a rebel delegation to the White House for talks on Friday.
Those announcements followed a new round of NATO airstrikes early on Thursday that hit Gaddafi's fortified compound in Tripoli. Just hours beforehand, the Libyan leader had appeared on state TV for the first time since his son was killed nearly two weeks ago. Before his appearance, rumours swirled that he had been killed or injured.
Reporters were shown the airstrike damage by Libyan officials, including one who said Gaddafi and his family had moved away from the Bab al-Aziziya compound some time ago. One missile appeared to have targeted some sort of underground bunker at the compound - a sprawling complex of buildings surrounded by towering concrete blast walls.
NATO, which has hit the Libyan capital repeatedly this week, said Thursday's attack successfully hit "a large command and control bunker complex in downtown Tripoli that was used to coordinate attacks against civilian populations."
A local journalist and another resident in Tripoli, reached by telephone from Egypt, told The Associated Press that there have been protests this week in at least three neighbourhoods in the capital, accompanied by exchanges of gunfire between opposition activists and Gaddafi forces. Both spoke only on condition of anonymity out of fear of reprisals.
When residents of Tripoli tried to protest against Gaddafi earlier in the uprising, gunmen in speeding cars tore through and fired wildly into the crowds, making many fearful to go out in the streets and demonstrate.
The local journalist said residents are deeply frustrated by a severe fuel shortage that forces some motorists to spend up to three days in line at gas stations.
The head of the rebels' transitional government, Mustafa Abdul-Jalil, said during a high-level visit to London on Thursday that Gaddafi opponents in Tripoli were in the process of acquiring weapons and predicted they would eventually contest regime forces in the capital.
"Tripoli is surrounded both internally and externally, and every day its sons go out and execute a few limited operations, perhaps to acquire some weapons," Abdul-Jalil said. "Tripoli will rise to get rid of this regime."
Britain said in talks it would supply police officers in rebel-held eastern Libya with uniforms and body armour, but so far - like other governments - is declining to provide military weapons.
The rebels control most of eastern Libya, while Gaddafi controls most of the west including Tripoli. The besieged port city of Misrata - about 200km southeast of Tripoli - is the only rebel stronghold in the west. Local doctors say more than 1000 of its residents have been killed in the fighting and shelling during the siege by Gaddafi's forces.
According to NATO, Gaddafi's forces dispatched a number of small speedboats to attack Misrata's port early on Thursday, but they were repelled by Canadian, British and French warships on the scene.
In Tripoli, Libyan government spokesman Moussa Ibrahim said three people were killed in Thursday's NATO strikes - a local official and two Libyan journalists who were making a documentary about the hundreds of Libyan civilians who have been sleeping in Gaddafi's compound to show support for their leader.
Ibrahim fumed at the persistent airstrikes, which are aimed at pressuring Gaddafi to end his 42-year authoritarian rule.
"All they want is to break our morale, to cause death and destruction everywhere," Ibrahim said. "People are being killed, every single day, every single night."
At the compound, there was a large hole in the ground near stairs leading to an underground passageway. A missile appeared to have landed and penetrated through a smaller hole before blowing up the gaping crater shown to reporters - a pattern typical of bunker-busting bombs.
Another missile made a small, charred hole in a large concrete area that appeared to serve as a corridor between buildings. Yet another dug a crater close to where khaki tents were strung up. A building described as a VIP reception area had part of its facade blown away.
Gaddafi's compound has been a frequent site of recent airstrikes, including one on April 30 that killed the leader's son, Seif al-Arab. Officials said Gaddafi was in the compound when that strike occurred but escaped unharmed.
NATO has repeatedly said all its targets in Libya are military and that it is not targeting Gadhafi or other individuals. In its latest update on Thursday, NATO denied targeting the North Korean Embassy in Tripoli - a response to a report by the Libyan state news agency JANA that the embassy had been damaged during one of this week's strikes.
Gaddafi had seven sons and one daughter. He also had an adopted daughter who was killed in 1986 when a US airstrike hit the Bab al-Aziziya compound in retaliation for a bombing attack on a German disco in which two US servicemen were killed.
In an apparent effort to dispel rumours that Gadhdfi himself had been killed, Libyan state TV showed him meeting tribal leaders, but did not record him speaking. To authenticate the scene, the camera zoomed in on the date on a TV monitor in the room, which read Wednesday, May 11. It was apparently recorded at the hotel where foreign correspondents must reside in Tripoli. Gaddafi did not make himself available to them.
The last time Gaddafi had been seen in public previously was April 9, when he visited a school in Tripoli.
Intensified NATO airstrikes on Gaddafi's forces across Libya have given a boost to rebels fighting to oust the regime. In all, NATO said, the alliance has carried out more than 2400 airstrikes since March 31 as part of the effort to assist the rebels and pressure Gaddafi to relinquish power.
Even though some of the recent reports of rebel advances are difficult to confirm, they seem to represent a major boost for the opposition's military prospects after weeks of stalemate on several fronts.
The United States has still made no decision on whether to formally recognize the rebels' Transitional National Council as Libya's legitimate government, though it has been boosting its support for the opposition in recent weeks.
President Obama has authorized $US25 million in non-lethal assistance, and thee first shipment of that aid - 10,000 ready-to-eat meals from Pentagon stocks - arrived in Benghazi this week.
The French Foreign Ministry said on Thursday that a Frenchman was killed at a police checkpoint in Benghazi, and four other French citizens were detained. Rebel officials said the victim was a military contractor, and he was shot in the back on Wednesday in unclear circumstances. His name was not released.
