PORT BREGA, Libya — Dispirited rebel fighters continued their headlong retreat across eastern Libya on Wednesday, surrendering a strategic oil city they captured just three days earlier and fleeing eastward by the hundreds.

Forces loyal to Libyan leader Moammar Gadhafi appeared poised late in the day to seize a second oil refinery city, Port Brega, as rebels in gun trucks near the city turned and fled at the sound of exploding rockets and artillery. Gadhafi's men had pushed rebels out of Ras Lanuf, site of a petrochemical complex and port, Wednesday morning.

Escaping rebels poured through the western gate of the crucial crossroads city of Ajdabiya, where allied airstrikes Saturday ended a 10-day government siege. Some rebels vowed to make a bloody stand in the nearly deserted city, but others fled in panic.

Most of the rebels in Ajdabiya had retreated 130 miles from Ras Lanuf since daybreak. Since early Tuesday, rebel forces arriving in Ajdabiya have backpedaled more than 200 miles in a desperate attempt to avoid confronting Gadafi's better armed and better trained forces.

The rebel effort was plagued by confusion and dissension. Clusters of volunteer fighters bickered over tactics and weapons, with many refusing to take orders from defecting army regulars nominally in command. Others demanded to know why allied warplanes were not attacking their enemy, and why tanks and rocket batteries captured from Gadhafi's men were not in use.

Rebels in gun trucks with mounted antiaircraft guns, heavy machine guns and recoilless rifles seemed unwilling to fire on advancing government troops. Many rebel gunners seemed content to melt away and hope - or pray, as one said - that allied airstrikes would save them.

It was unclear how far Gadhafi would push his forces and expose his men and weapons to allied warplanes in the flat, open desert between Port Brega and Ajdabiya.

The chaotic retreat sent rebel vehicles speeding past burned-out hulks of government tanks, rocket launchers and troop carriers destroyed in allied airstrikes at Ajdabiya. It was uncertain Wednesday whether warplanes had attacked government forces pushing relentlessly eastward.

"We're hearing that the planes are bombing near Ras Lanuf"" said Ashral Kwaifi, an oil engineer turned rebel at a checkpoint north of Ajdabiya.

But Kwaifi conceded that the information was little more than conjecture. With no cellphone coverage in the war zone, rebels often repeat rumors spread by passing motorists.

Last weekend, airstrikes cleared the way for a rapid rebel advance by demolishing government armor. Late Sunday, rebel fighters were within 50 miles of Sirte, Gadhafi's hometown with a well-defended garrison. The rebels had advanced 150 miles in less than 24 hours.

But they have been running from government forces since. Among those fleeing were soldiers who defected last month from Gadhafi's army in eastern Libya - men who opposition leaders say are leading undisciplined rebel forces.

Many rebels have rebuked regulars and commandos brought in by Gadhafi's former interior minister, Gen. Abdul Fatah Yunis, a defector whom opposition leaders describe as the rebel commander. They say they don't trust Yunis or his troops because of their longstanding service to Gadhafi.

Some rebels accused commandos and army defectors of hoarding tanks and Grad rocket systems abandoned by Gadhafi's fighters during airstrikes and recovered by opposition forces. Those heavy weapons have not been seen at the front.

"Where are our tanks and Grads?" asked Hamsa Mohammed Cherkasi, 25, a rebel fighter just outside Port Brega as the crash of government artillery sounded nearby. "That's all we have to stop these Gadhafi people, but the army is keeping them for itself."

At an army base in Benghazi, Yahya Abdulsalam, a rebel guard, said nine captured government T-72 Soviet-made tanks inside the garrison could not be operated because rebels don't know how to turn on the engines.

In an attempt to preclude coups, Gadhafi outfitted army units in eastern Libya with old, outdated or poorly maintained weapons.

The rebels have no command and control, and no effective leadership. Volunteer fighters in each gun truck or private car make their own decisions, often after animated arguments with gunmen from other vehicles.

'Tactical withdrawal'

In Benghazi, the rebels' de facto capital, residents and opposition leaders seemed confident that allied airstrikes would protect them from Gadhafi's armored columns. There were few gun trucks on the streets and no signs of defensive barricades.

A rebel military spokesman, Col. Ahmad Omar Bani, called the wholesale retreat a "tactical withdrawal." He said rebel fighters were confronting government forces around Port Brega, and he promised that Ajdabiya would not fall.

But several rebel gun trucks were seen fleeing Ajdabiya late in the day, joining cars packed with children, bedding and suitcases speeding north through undefended desert toward Benghazi.

Also Wednesday, Human Rights Watch accused Gadhafi's forces of planting three dozen anti-personnel mines and two dozen anti-vehicle mines in Adjabiya.

The New York-based group cited the electricity director for eastern Libya, Abdal Minam al-Shanti, who said two anti-personnel mines detonated when a truck ran over them, but no one was hurt. Al-Shanti said a civil defense team found and disarmed more than 50 mines in what Human Rights Watch described as a heavily traveled area.

"Libya should immediately stop using antipersonnel mines, which most of the world banned years ago," Peter Bouckaert, emergencies director for the agency in Libya, said in a statement.

The Associated Press contributed.