Updated

Dozens of Al Qaeda prisoners who were picked up after fleeing Tora Bora stormed their Pakistani guards on a bus Wednesday, seizing their weapons and opening fire in a mass escape that left six guards and seven fighters dead.

Pakistani helicopter gunships pursued the fugitives into the night through the rugged mountains near the Afghanistan border. Twenty-one fighters were recaptured but 20 others were still missing.

The bloody escape spilled onto a dusty road near the town of Parachinar, where the band of militant fighters, mostly Arabs, had been held overnight after capture while crossing the border from the Tora Bora region of eastern Afghanistan.

"One of the Arabs shouted 'Allahu Akbar!' and with that slogan the others attacked," bus driver Rehman Ali told The Associated Press. An Al Qaeda fighter took the wheel of the bus, drove off the road and rolled it over in the melee.

Tribal security officials said the area was sealed off and "a hectic search is in progress."

The fighters were among 156 Al Qaeda members taken prisoner by provincial officials since Sunday after the warriors escaped into Pakistan along rugged mountain trails. They were being transferred in a convoy of three buses and two trucks to a larger jail.

Hundreds of Al Qaeda fighters were driven out of cave hideouts and deep mountain valleys in the Tora Bora region over the past few days after weeks of unrelenting U.S. bombing and ground attacks by tribal Afghan fighters backed by U.S. and British special forces.

In Tora Bora, U.S. helicopters ran dangerous night missions up the valleys looking for holdouts or stragglers, while Afghan fighters brought out more prisoners and documents from snow-bound hideouts. The U.S. bombing had stopped. The whereabouts of Al Qaeda leader Usama bin Laden remained a mystery.

"I don't know if he is still in the Tora Bora area, if he's been injured or killed, or if he has left Afghanistan," said Gen. Richard Myers, chairman of the Joint Chiefs of Staff.

U.S. forces were keeping up the search for Al Qaeda fighters and bin Laden, concerned that they could escape Afghanistan to plan more terrorism, Defense Secretary Donald H. Rumsfeld said Wednesday.

"I think it would be a mistake to say Al Qaeda is finished in Afghanistan at this stage," Rumsfeld said at a Pentagon news conference.

In southern Afghanistan, a group of Taliban fighters attacked the forces of Kandahar Gov. Gul Agha in an effort to capture the town of Takhta-e-Pul, witnesses said.

People coming by road from Kandahar to the Pakistani border town of Quetta said the attack was repulsed and that Gul Agha beefed up security at the village.

Journalists traveling in a convoy from Kandahar said they saw no sign of fighting in the area. The provincial intelligence chief, Haji Gulalai, denied an earlier report that fighting had closed the road.

"Everything is under our control," he told the AP.

A vanguard of 200 British troops, meanwhile, prepared to take positions in the Afghan capital, Kabul, as a peacekeeping force. Their deployment was to coincide with the Saturday inauguration of the six-month interim government to be led by Prime Minister Hamid Karzai.

Military advisers from 17 countries met in London to nail down details of the expanded international peacekeeping mission and the U.N. Security Council was poised to approve the force, possibly by Thursday. As many as 5,000 soldiers eventually may join the force.

Karzai said bin Laden and Mullah Mohammed Omar, the Islamic cleric who led the brutal five-year Taliban regime, would not be welcome in the new Afghanistan.

"There's no way we can allow them to stay. They've killed our people, they have destroyed our land. We will finish them to the end," Karzai said in Rome, where he received the blessing of exiled King Mohammad Zaher Shah, a fellow Pashtun tribesman.

Afta Gul, a commander of the eastern tribal forces, said only a few of his men remained in the White Mountains of the Tora Bora area where an estimated 1,000 Al Qaeda members had taken refuge.

Some captives "are telling us stories about Usama giving a speech 14 days ago and then leaving, but these men are not very credible," Gul said. "I have heard that Usama has shaved his beard and gone to Pakistan, but no one can say for sure."

Afghan fighters returned to their base with piles of maps and Arabic-language documents from caves they had searched, including a topographical map marking mortar positions and their field of fire, and a training manual on aiming tank fire.

Meanwhile, a top alliance official said the eastern alliance's governing council, or shura, had met in Jalalabad on Friday and rebuked two senior tribal leaders who some shura members accused of helping Al Qaeda fighters flee Tora Bora.

Hundreds of Al Qaeda family members escaped, and top Al Qaeda commanders may have been among them, said the official, who attended the meeting and spoke on condition of anonymity for fear of retribution.

Pakistan dismissed allegations that its authorities also protected Al Qaeda fugitives.

At a U.S. Marine base at Kandahar's airport, FBI agents questioned 15 Al Qaeda and Taliban captives.

They wanted information about the Sept. 11 terrorist attacks and last year's suicide assault on the USS Cole in Yemen which killed 17 sailors.

Five other captives, including an American and an Australian who fought with the Taliban, were interrogated aboard the USS Peleliu in the Arabian Sea.

In other developments:

— Britain announced Wednesday it would reopen its embassy in Afghanistan after a 12-year break. The American embassy reopened Monday as a liaison office.

— The number of Afghan refugees camped along the northern border with Tajikistan has dropped from as many as 10,000 to about 3,000 since the United States opened its campaign to crush the Taliban and Al Qaeda, the Russian border guard service said.