Residents of Libya's dissident-held East, frenzied by a deadly crackdown by Moamer Kadhafi's crumbling regime, vowed on Thursday to march on the capital Tripoli as a string of towns famous as World War II battlegrounds fell under their control.

With big chunks of the Army defecting to the week-old protest movement leaving much of the East outside government control, top commanders queued up to talk to foreign correspondents newly able to access a country ruled with an iron fist since Kadhafi's 1969 coup.

US President Barack Obama described the scorched earth response of the regime's remaining loyalists as "outrageous," leading an international outcry over a death toll now running into hundreds.

World governments scrambled to evacuate stranded nationals from an oil-rich country falling into mounting lawlessness as world crude prices soared.

Eastern towns from the Egyptian border through the famed Allied-Axis battlefield town of Tobruk to Libya's second city of Benghazi have fallen to local militias or mutinous troops, residents said.

The streets of one of the East's major towns, Al Baida, were calm on Thursday morning but shuttered shopfronts still bore the bulletholes of recent fighting.

"Our goal now is Tripoli," one protester told a town hall meeting addressed by defecting generals. "If Tripoli cannot liberate itself."

The streets of the capital were deserted on Thursday morning after persistent gunfire in the Eastern suburbs through the night.

A dozen Army and police commanders came forward in Al Baida to pronounce their support for the popular revolt, each one receiving wild applause from the crowd.

"I have left my job and come to Al Baida in solidarity with my people," said the police general Salah Mathek, a CID chief.

"I will be at the forefront of confronting any attack from outside. They say I am a traitor but I have principles."

General Abdul Aziz al-Busta said he had refused orders to fire on civilian demonstrators as the uprising erupted last week, inspired by the fall of veteran strongmen in neighbouring Egypt and Tunisia.

"They asked us to confront the people and I refused. We cannot use our weapons on our young," he said.

Residents spoke of a bloodbath as the regime tried to cling on to power in the Eastern Cyrenaica region, long a bastion of dissent.

The main hospital in Al Baida was treating a raft of gunshot casualties, among them two medics, fired on as they attempted to care for the wounded.

"They fired at us randomly in the city centre. They even fired at people trying to help us," said a 27-year-old who was shot in the thigh.

Mohamed Ebreke, a 26-year-old Red Crescent staffer, was shot in the side as he tried to administer first aid to demonstrators outside a military barracks near the city.

"We were transporting the wounded when I was hit," he said.

A protester, who would give his name only as Nasser such is the fear the regime still commands, said: "I just want the world to see our misery.

"This is not something new. This is something we've been living with for 40 years."

Eastern Libya has long complained of discrimination in the allocation of resources by the regime of Kadhafi, who boasts links with the bedouin nomads and former nomads of the desert south and the arid central coast.

"In the East, they never did anything for us," complained police Sergeant Khaled Abdul Aziz.

"All that you see was created by the king," he said referring to King Idriss, the Western-backed monarch Kadhafi overthrew four decades ago.

"We all joined the revolution after seeing the mercenaries killing our youth. That was the turning point. It was a violation of our honour."

The Libyan leader has long sought to be a major player in Africa's affairs, backing rebel groups across the continent, and it is a constant refrain of the protest movement that his praetorian guard is largely recruited among mercenaries from sub-Saharan Africa.

Obama urged the world to unite to hold Libya accountable for the crackdown while British foreign secretary William Hague said he wanted an international investigation into the "atrocities" taking place.

In his first televised response to Kadhafi's decision to unleash vengeance on demonstrators, Obama promised to deploy a "full range of options" to halt "outrageous" bloodshed.

Britain joined a growing list of governments sending in aircraft to evacuate nationals. China arranged to evacuate half of its 30,000 citizens on four ferries chartered from Greece.a