TRIPOLI (Reuters) - Libyan leader Muammar Gaddafi fought an increasingly bloody battle to hang on to power on Monday when anti-government protests against his 41-year rule struck the capital Tripoli after days of violence in the east.
Residents reported gunfire in parts of Tripoli and one political activist said warplanes had bombed the city.
Forces loyal to Gaddafi had killed dozens of people across the country, human rights groups and witnesses said, prompting widespread condemnation from foreign governments.
No independent verification of the reports was available and communications with Libya from outside were difficult.
But a picture emerged that suggested the survival of a leader who has loomed large on the world stage for decades and controls vast reserves of oil was in jeopardy.
"What we are witnessing today is unimaginable. Warplanes and helicopters are indiscriminately bombing one area after another. There are many, many dead," Adel Mohamed Saleh said in a live broadcast on Al Jazeera television. "Anyone who moves, even if they are in their car they will hit you."
Two Libyan fighter jets landed in Malta, their pilots defecting after they had been ordered to bomb protesters, Maltese government officials said.
An analyst for London-based consultancy Control Risks said the reported air attacks indicated the end was near for Gaddafi.
"These really seem to be last, desperate acts. If you're bombing your own capital, it's really hard to see how you can survive, " its Middle East anaylst Julien Barnes-Dacey said.
"We don't know what is going on, all we can hear are occasional gun shots," one Tripoli resident said.
The demonstrations spread to the Mediterranean Sea capital after several cities in the east, including Benghazi, appeared to fall to the opposition, according to residents' accounts.
Human Rights Watch said at least 233 people had been killed in five days of violence, but opposition groups put the figure much higher.
PARLIAMENT BUILDING ON FIRE
A coalition of Libyan Muslim leaders told all Muslims it was their duty to rebel against the Libyan leadership because of its "bloody crimes against humanity".
The building where the General People's Congress, or parliament, meets in Tripoli was on fire on Monday, as was a police station in an eastern suburb, witnesses said.
Al Jazeera television quoted medical sources as saying 61 people had been killed in the latest protests in Tripoli.
It said security forces were looting banks and other government institutions in Tripoli, and protesters had broken into several police stations and ransacked them.
One of Gaddafi's sons said the veteran leader would fight the revolt until "the last man standing". But a coalition of Libyan religious leaders told all Muslims it was their duty to rebel against the Libyan leadership because of its "bloody crimes against humanity".
Some analysts suggested Libya was heading for civil war.
"Libya is the most likely candidate for civil war because the government has lost control over part of its own territory," said Shadi Hamid, director of research at the Brookings Doha Centre in Qatar.
"I think what's going to happen is going to be much more chaotic than what we saw in Egypt or Tunisia. Gaddafi and his sons don't have anywhere else to go...They are going to fight," said North Africa analyst Geoff Porter, contributor to political risk consultancy Wikistrat.
Output at one of Libya's oil fields was reported to have been stopped by a workers' strike and some European oil companies withdrew expatriate workers and suspended operations. Most of Libya's oil fields are in the east, south of Benghazi.
Anti-government protests have also broken out in the central town of Ras Lanuf, the site of an oil refinery and petrochemical complex, Libya's Quryna newspaper said on its website on Monday.
In signs of disagreement inside Libya's ruling elite, the justice minister resigned in protest at the "excessive use of violence" against protesters. In India, Libya's ambassador said he was resigning in protest at the violent crackdown.
Libya's deputy prime minister denied reports that Gaddafi had fled to Venezuela -- ruled by his friend and fellow revolutionary President Hugo Chavez .
THREATS AND PROMISES
Gaddafi's son Saif al-Islam Gaddafi appeared on national television on Sunday night, saying the army would enforce security at any price to put down the revolt. He also promised reform and wage rises.
"We will keep fighting until the last man standing, even to the last woman standing," he said.
But people in Tripoli expressed anger at the speech.
A Libyan woman who gave her name as Salma, said: "He threatened the Libyan people with killing, hunger and burning. He did not offer mercy for the souls of the martyrs who were killed."
Gaddafi supporters were in central Tripoli's Green Square on Monday, waving flags and carrying his portrait, Libyan state TV showed.
But the anger unleashed after four decades of rule by Gaddafi mirrors events in Egypt where a popular revolt overthrew the seemingly impregnable President Hosni Mubarak 10 days ago.
In Benghazi, cradle of the uprising, protesters appeared to be largely in control after clashes with troops and police in which dozens of civilians were killed.
"Youths with weapons are in charge of the city. There are no security forces anywhere," University of Benghazi professor Hanaa Elgallal told Al Jazeera television.
Salahuddin Abdullah, a self-described protest organiser, said: "In Benghazi there is celebration and euphoria ... The city is no longer under military control. It is completely under demonstrators' control."
There were reports that soldiers who refused to fire on civilians were executed by officers in Benghazi.
"We have buried today 11 bodies of soldiers who refused to fire on civilians and were executed by Gaddafi officers. The bodies were cut, heads in one side and legs in the other," said Elsanous Ali Eldorsi, a retired judge in Benghazi.
At least nine towns in the east were under the control of protesters loyal to tribal groups, the president of the International Federation for Human Rights in France said.
Support for Gaddafi, who seized power in 1969, among Libya's desert tribes was also waning. The leader of the Al-Zuwayya tribe in the east threatened to cut oil exports unless authorities halted "oppression of protesters".
Libya is Africa's fourth biggest oil exporter, producing 1.6 million barrels a day. The oil price jumped $3 to $89.50 a barrel for U.S. crude on fear the unrest could disrupt supplies.
(Reporting by Tarek Amara and Christian Lowe; additional reporting by Brian Love and Daren Butler; Writing by Jon Hemming: Editing by Angus MacSwan)