Qaddafi's troops capture oil town of Brega

Speed of advance by Qaddafi's forces may overtake drawn-out diplomatic wrangling on whether or how to impose a no-fly zone.

Doctors working at a local hospital join other protesters in calling for a no fly zone over Libya during a rally in Benghazi today.

Muammar Qaddafi's troops seized the strategic Libyan oil town of Brega today, forcing rebels to retreat under a heavy bombardment while world powers considered imposing a no-fly zone.

Losing Brega and its refinery further limits rebel access to fuel after the insurgents were pushed out of Ras Lanuf today, another major oil terminal some 100 kilometres to the west along the coast road where all of Libya's important towns are located.

Defeated rebel soldiers were demoralised. "There's no uprising any more," said rebel Nabeel Tijouri, whose heavy machinegun had been destroyed in the fighting. "The other day we were in Ras Lanuf, then Brega, the day after tomorrow they will be in Benghazi."

A Libyan government army source told state television: "Brega has been cleansed of armed gangs."

Brega is 220km south of the rebel stronghold of Benghazi, with the town of Ajdabiyah the only sizeable town standing in the way. From Ajdabiyah there are roads to either Benghazi or Tobruk, close to the border with Egypt.

Libya's flat desert terrain means the government's air supremacy and big advantage in tanks outweighs the rebels' enthusiasm and light weaponry. Only towns and cities provide some cover for the insurgents and partially even the odds.

One rebel fighter, Masoud Bwisir, interviewed at the western gate of Ajdabiyah, said: "He's out of Brega. He's on the way, maybe in half an hour his rockets will reach us here."

The speed of the government advance may overtake drawn-out diplomatic wrangling on whether or how to impose a no-fly zone.

The United States said a call by the Arab League for a UN no-fly zone over Libya was an "important step", but while Washington said it was preparing for "all contingencies", it has remained cautious over endorsing direct military intervention.

The Arab League secretary general, Amr Moussa, said the League had "officially asked the UN Security Council to impose a no-fly zone against any military action against the Libyan people".

That satisfies one of three conditions Nato agreed on Friday are needed for it to take on the task of policing Libyan air space; that of strong Arab support. The others are proof that its help is needed and a UN Security Council resolution.

A Nato official said: "Regional support is one of the three conditions. For us the three conditions have not changed, and we do not have a UN mandate."

The United States does not want to appear to be leading the drive to oust Colonel Qaddafi and made no proposal for an emergency meeting of the UN Security Council.

Even if the Security Council does meet to discuss a no-fly zone, it is far from clear whether it would pass a resolution as veto holders Russia and China have both publicly opposed the idea.

Fresh from crushing the revolt in Zawiyah, west of the capital Tripoli, elite government troops and tanks turned to Misrata, Libya's third biggest city and the only pocket of rebel resistance outside the east.

But a mutiny among government troops stalled their advance for a second day today, rebels said.

Mohammed, one of the rebel fighters, told Reuters by telephone: "From the early morning they [the government troops] are fighting among each other. We hear the fighting.

"This division between them came to us from God. Just when we thought the end was coming, this happened. Now we are waiting to see what will happen."

The events could not be confirmed independently. Journalists have been prevented from reaching the city by the authorities. A government official in Tripoli dismissed the reports as rumours.

A government spokesman, Mussa Ibrahim, said: "There is a hard core of al Qa'eda fighters there. It looks like a Zawiyah scenario. Some people will give up, some will disappear. Tribal leaders are talking to them. Those who stay behind, we will deal with them accordingly."

It took a week of repeated assaults by government troops, backed by tanks and air power, to crush the uprising in Zawiyah, a much smaller town 50km west of Tripoli.

The death toll in Zawiyah is unknown but much of the town was destroyed, with buildings around the main square showing gaping holes blown by tank rounds and rockets. Colonel Qaddafi's forces bulldozed a cemetery where rebel fighters had been buried.

After fighting ceased in Zawiyah on Friday, one soldier there was asked about the fate of rebels. He made a throat-cutting gesture and laughed.

As in Zawiyah, the rebels in Misrata were heavily outgunned.

"We are bracing for a massacre," said Mohammad Ahmed, a rebel fighter. "We know it will happen and Misrata will be like Zawiyah, but we believe in God. We do not have the capabilities to fight Qaddafi and his forces. They have tanks and heavy weapons and we have our belief and trust in God."

Libyan security forces have launched a wave of "arbitary arrests and forced disappearances" in the capital to stamp out protests against Colonel Qaddafi's rule, Human Rights Watch said today. The New York-based group said it compiled evidence from Tripoli residents of scores of people being detained if they helped organise or took part in anti-government protests, or if they were suspected of speaking to foreign media.

Many governments say Colonel Qaddafi violently repressed an uprising against his rule. The Libyan leader said the revolt was conducted by a small group of al Qa'eda operatives backed by foreign forces bent on destroying Libya.

Sarah Leah Whitson, Middle East and North Africa director at Human Rights Watch, said in a statement: "Qaddafi and his security forces are brutally suppressing all opposition in Tripoli, including peaceful protests, with lethal force, arbitrary arrests, and forced disappearances.

"Given Libya's record of torture and political killings, we worry deeply about the fate of those taken away," she said.

Colonel Qaddafi lost control over large parts of the country after a revolt against his rule last month. The rebel's stronghold has been in the east of Libya and in Tripoli, to the west, protests have been small and quickly dispersed by security forces. Ms Whitson said: "The arrests and disappearances in Tripoli have cowed many who were peacefully protesting against the government. It shows how much the government headed by Qaddafi is relying on intimidation."