By Maria Golovnina and Michael Georgy
TRIPOLI (Reuters) - Intense automatic gunfire erupted in the Libyan capital Tripoli on Sunday, the first such outbreak in Muammar Gaddafi's main stronghold in a two-week-old insurrection against his 41-year-old rule.
It was unclear who was doing the shooting, which started just before daybreak, or what had caused it. Machinegun volleys, some of them heavy caliber, reverberated around central Tripoli along with ambulance sirens, pro-Gaddafi chants, and a cacophony of car horns as vehicles sped through the vicinity.
Government spokesman Mussa Ibrahim denied any fighting was under way in the capital, saying the gunfire was to mark the army's recapture of several cities from rebel forces.
"These are celebrations because government forces have taken control of all areas to Benghazi and are in the process of taking control of Benghazi," Ibrahim said, referring to Libya's rebel-controlled second largest city situated in the far east.
But Benghazi and the Libyan coast east of the port city of Ras Lanuf remained in rebel hands, Reuters correspondents there said.
State television said government forces also had retaken the important coastal cities of Zawiyah and Misrata, to the immediate west and east of Tripoli.
While a resident in Misrata insisted the city still under rebel control, the fate of Zawiyah was unclear on Sunday after government troops and tanks launched a series of fierce attacks there the previous day that were repulsed by the rebels.
Gaddafi's forces also launched a counter-attack on Bin Jawad, a town west of Ras Lanuf captured by rebels on Saturday.
One fighter returning wounded from the frontline town said the Gaddafi loyalists had attacked with machineguns and rocket-propelled grenades (RPGs).
Asked what he had seen, he replied: "Death."
Other rebel fighters in Ras Lanuf said they had received news of the attack by phone from the frontline. "People tell us in Bin Jawad there are Gaddafi forces. Some rebels have been hit by snipers," Khamis al-Libi, a rebel fighter, said.
The resilience of Gaddafi's forces in the face of the widespread rebellion and their ability to counter-attack will increase fears that Libya is heading for a protracted civil war rather than a swift revolution as seen in Tunisia and Egypt.
Salem Ghazy, a Tripoli businessman, was part of a group of security forces and civilians who were firing into the air from automatic weapons in Tripoli and brandishing posters of Gaddafi.
"Libya is united. We will fight these forces that are trying to ruin the country. These forces are backed by outside powers," he said.
A resident near the central Green Square said: "They are shooting in celebration. It's because they said the towns where the rebels have been fighting have been liberated."
Ibrahim denied there was any fighting in Tripoli.
"Everything is safe. Tripoli is 100 percent under control," he said, while adding: "I would like to advise you not to go there for your safety."
Rebel commander Abdelwahabin said most people in Tripoli opposed Gaddafi.
"All Libyans are unanimous about overthrowing Gaddafi, even in Tripoli, but they are unable to move there as all the security forces are dressed in civilian clothing, mixing with anyone trying to protest," he said.
As of Saturday night, Libyan rebels had dug into positions in Zawiyah after withstanding two armored assaults by government forces, but it was not possible to reach anyone in the town early on Sunday morning.
With rifle-toting insurgents on rooftops and manning checkpoints on streets leading into the center of Zawiyah, the rebels had said they were bracing for another tank and artillery attack by government forces on Sunday.
Deputy Foreign Minister Khaled Kaim told reporters late on Saturday that Zawiyah was "quiet and peaceful. "We hope by tomorrow morning life will be back to normal."
A doctor in Zawiyah, some 50 km (30 miles) west of Tripoli, said at least 30 people, mostly civilians, were killed during fighting on Saturday that wrecked the town center, raising to at least 60 the death toll from two days of battles.
BRITISH TROOPS SEIZED
Britain's Sunday Times reported that rebels had seized a British SAS special forces unit of up to eight soldiers escorting a junior diplomat in eastern Libya on a secret diplomatic mission to make contact with opposition leaders.
The SAS intervention apparently angered opposition figures who fear Gaddafi could use any evidence of Western military intervention to sway patriotic support away from the uprising, according to the London paper. The report could not immediately be confirmed.
In a French newspaper interview, Gaddafi said he was embroiled in a fight against Islamist terrorism and expressed dismay at the absence of support from abroad.
"I am surprised that nobody understands that this is a fight against terrorism," Gaddafi told le Journal du Dimanche.
"Our security services cooperate. We have helped you a lot these past few years. So why is it that when we are in a fight against terrorism here in Libya no one helps us in return?"
Western leaders have denounced what they call Gaddafi's brutal response to the uprising, and the International Criminal Court said he and his inner circle face investigation for alleged targeting of civilians by his security forces.
But the opposition, while assembling an inspired fighting force, has failed to produce a convincingly clear leadership, a weakness Gaddafi hopes to exploit as the struggle continues.
The International Energy Agency said the revolt had blocked about 60 percent of Libya's 1.6 million bpd (barrels per day) oil output. The drop, due largely to the flight of thousands of foreign oil workers, will batter the economy and have already jacked up crude prices abroad.
(Additional reporting by Michael Georgy in Tripoli, Alexander Dziadosz in Ajdabiya, Mohammed Abbas in Bin Jawad, Stefano Ambrogi in London, Nick Vinocur in Paris and Tom Pfeiffer in Benghazi; Writing by Mark Heinrich and Jon Hemming; Editing by Michael Roddy)