Their tactics may have had at least a partial payoff. An intense U.S. bombing campaign as well as commando operations by Afghans and American special forces troops left more than 200 Arab, Chechen, and Pakistani Al Qaeda fighters dead and at least 25 captured at the weekend, says Hazrat Ali, security chief of Nangrahar Province. But bin Laden’s whereabouts are still unknown–and hundreds more Al Qaeda fighters may have escaped too. According to the Pentagon, an estimated 1,000 to 2,000 Al Qaeda forces were holed up at Tora Bora. Provincial governor Haji Abdul Qadir believed that between 400 and 1,000 of them–including Saudis, Sudanese, Egyptians, Libyans, Yemenis, Chechens and other non-Afghan fighters–were still there as late as last week. For now, less than 280 have been accounted for.

Those at large may have fled Afghanistan entirely. Weather permitting, there are at least three escape routes out of Tora Bora to nearby Pakistan, and another two main trails out of the nearby city of Jalalabad. One of the tracks out of Tora Bora winds down about 13 miles to the town of Khogiani and eventually to the Torkham border, crossing through the Khyber Pass. A second involves a circuitous switchback via the town of Asrow and on to Parachinar in Pakistan. The shortest route goes directly from Tora Bora towards Parachinar, a trip that can be made in a single day.

U.S. allies did try to stop bin Laden taking advantage of the age-old smuggling routes that lead out of Tora Bora. On the Pakistan side of the 1,344-mile border, Islamabad mobilized more than 4,000 of its soldiers, sending them out into the semi-autonomous–and largely lawless–frontier areas. It was the first time federal troops have ever been deployed in these regions, where tribal custom, not Pakistani laws, hold sway. The soldiers, bolstered by air reconnaissance missions, were concentrated along the 25-mile stretch of border between Tora Bora and Parachinar. Given recent snowfall, “it would be very difficult for Al Qaeda to get out as a body,” said coalition spokesman Kenton Keith in Islamabad.

Still, some do seem to have beaten the odds. “It’s a very complicated area to try to seal,” U.S. Defense Secretary Donald Rumsfeld said recently. “And there’s just simply no way you can put a perfect cork in the bottle.” In addition, many foreign fighters have cultivated sympathetic acquaintances among local Afghan villagers in the Tora Bora area. By many accounts, these locals have been willing to provide aid to the Al Qaeda members.

Last week, one grimy warrior from the Khogiani tribe told NEWSWEEK that Arabs were trying to get his tribesmen to join the Al Qaeda side. “They asked us, ‘why are you fighting for money [with the anti-Taliban forces?] If you fight for us and die you’ll be holy martyrs. But if you die in the service of anti-Taliban commanders, it will be an unholy death.’” Akbar Khan, a Kalashnikov-wielding young man from Sarwarkala village, grumbled that pro-U.S. commanders “promised us $50 a week but gave us nothing. I’m not a worm who can live on eating dirt.” Khan said he’s been hungry for two days, and promised, “I’ll wait just one more day–and then I’ll go fight for [the] Al Qaeda side because they’re offering to pay $160.”

One local from Bamokhel village told NEWSWEEK that he provided food and medicine for “the Arabs”–a term residents use to refer collectively to non Afghan fighters. To evade interrogation by anti-Taliban soldiers, the villager used a donkey specially trained to pick its way, unaccompanied, up the mountain to an Al Qaeda hideout. There, the foreigners put their shopping lists into a saddlebag, and the riderless donkey came back down again. “They asked for sweet dates and other foods” popular during the Ramadan fasting period, said the village man, his skin chapped and rough from the cold. “And they also asked for medicine.” He didn’t know what sort of medicines because the names were written in English; he’d had to ask a friend to get the items for him.

With such logistic support, Al Qaeda militants might have held out at Tora Bora much longer had it not been for the ferocious American bombardment. When anti-Taliban forces overran the gateway into the Tora Bora redoubt early last week, they found two main caves almost seven yards square which were camouflaged bunker-style munitions depots complete with wood and stone flooring. “We conducted an intense guerrilla battle for the entrance” to the valley, said group leader Abdul Malak, a member of the Hazrat Ali faction. “We chose 30 specially trained volunteers who were ready to sacrifice their lives.”

After nearly two hours of clashes, the anti-Taliban forces took a 0.6 mile-square area of caves and bunkers. They recovered Arabic-language documents, heavy weapons, several pick-up trucks “and a wireless radio that Osama and other Al Qaeda members used to talk secretly,” Malak claimed. But almost immediately, Arab fighters re-took the caves. Another day of sustained U.S. air attacks–carpet bombing, strafing from AC-130 gunships, and, finally, devastating 15,000-pound Daisy Cutter bombs–helped beat the Al Qaeda fighters back. By Tuesday, Ali’s troops had taken one of the two peaks of Enzeri Zur mountain, including a number of small caves extending 40 feet or so into the rock.

The devastated area contained many mementos of Al Qaeda’s foreign connections. In addition to bloodied clothing, singed trees and munitions fragments, there were depots of Chinese-made heavy machine-gun bullets and ammunition, plus Arabic-English and Arabic-Chinese books. At a destroyed Al Qaeda training camp, trees were singed and flattened. There were abandoned parallel bars, a French-language pamphlet on how to blow up bridges–and black-and-white circular targets with the bullet holes taped over so that they could be used again. The targets were printed with bold letters “NRA”–apparently a reference to the U.S.-based National Rifle Association–and had names and scores printed in Arabic. (Judging from the placement of the bullet holes, some of the Al Qaeda trainees weren’t very good shots.)

Many local Afghans insist that Arabs continued to steal out of Tora Bora as recently as last week. A villager named Dad Mohammed, from Dagga Zamarkhel village, claimed that as many as 30 foreigners left Tora Bora for Pakistan daily. They paid professional people-smugglers nearly $100 to lead them over smugglers’ routes controlled by sympathetic tribesmen of the Sulaimankhel clan, he said. Their destination was the Pakistani city of Parachinar, where local Pashtuns are well-disposed to Arabs because many of their own relatives work in the Gulf.

Unsolicited, Mohammed added that “Osama and [top aide Ayman al-] Zawahiri already left for Pakistan, via Kama, many days before.” But before he could say more, a Northern Alliance soldier walked by and Mohammed furtively slipped away. Like so many other reported Osama sightings, there was no independent verification available.