This dawn was different. The B52s were absent and the skies were quiet and clear. But the morning's peace was soon rudely ruptured. Hundreds of mujahideen warriors rushed forward from their bunkers and trenches. Their first target was the thousand or so hardcore Al Qaida fighters mounting a last ditch defence from the reinforced caves that riddle the huge mountain massif known as Tora Bora in eastern Afghanistan. Their second target was the man the Al Qaida fighters were defending: Osama bin Laden, the subject of the biggest manhunt in world history.

EYES PEELED: (From above to below) A marine in his fighting hole near Camp Rhino; anti-Taliban fighters go through munitions left behind in an Al Qaida cave bunker; bin Laden on TV

The assault at the beginning of last week failed in both its objectives. A few positions low down the steep mountains were captured but heavy machine gun and mortar fire from well-concealed bunkers prevented any significant gains. Casualties were suffered by both sides and some captives were taken.

Now the B52s are back, dropping "daisycutter" bombs in a bid to seal tunnel entrances and destroy the enemy's morale, and the mujahideen are preparing for a new attack. These days, however, the early predictions of swift victory are being scaled back. The job is a tough one, say mujahideen commanders and allied planners alike. It could take weeks, months even, to search and secure the whole area. And, several commanders pointed out last week, no one is even sure if bin Laden is there.

The battle at Tora Bora is a microcosm of the broader fight to wind up Al Qaida. The Arabs who were spitting their defiance at the world from its dusty peaks last week are an elusive enemy, well hidden with a number of covert supply routes and an unknown capability to cause further destruction. So is the organisation to which they belong. Key to the whole operation is intelligence. In Tora Bora last week, mujahideen commanders listened in on conversations between Al Qaida men on their radios. But it was difficult to pick up anything of value because all of them, Chechens, Arabs and Pakistanis alike, spoke in Arabic, a language few Afghans know.

"The other day we listened to them talking about 'the sheikh' and asking about his condition. We learned a lot from them," said Halim Shah, a senior mujahideen commander. "One of my fighters who speaks Arabic could translate."

And where's the linguistically gifted mujahid now?
"He's gone back to his village to look after his family."

Similar lapses have characterised the operation to snare top Al Qaida figures, Mullah Omar and the Taliban leadership who might be fleeing from the south of Afghanistan too. Omar was able to escape from Kandahar, on the back of motorbike according to one source, despite the presence of hundreds of US Marines at Camp Rhino and thousands of fighters loyal to Hamid Karzai, the new pro-West, royalist leader of the country. Now, admits General Tommy Franks, the commander of the American forces in the region, no one knows where Omar is. US special forces across southern Afghanistan have mounted roadblocks on the main roads and bridges to intercept Taliban officials and to prevent supplies reaching Kandahar. More aggressive ground patrols have been launched. But so far only a handful of the terrorist kingpins have been killed.

SMOKING HIM OUT: An Afghan warrior watches a US bombing raid on Tora Bora. Predictions of a quick victory are being revised

One place they may try looking for Mullah Omar, an Afghan source in Pakistan said, is the remote ridge of mountains lying east of the Kabul-Kandahar road and south of the eastern city of Khost. The fugitive Taliban leader has strong links with the tribes in the area-many are Hotaki like he is-and would shelter him. "He could hide there indefinitely," said the source.

But bin Laden is different. Few believe he really wants to spend the rest of his life on the run. "We have to be careful about assuming he wants to run and hide," said Anthony Cordesman, a former State Department official who is now at the Center for Strategic and International Studies in Washington. "I think this is someone who sees martyrdom as the goal."

Intelligence evidence seems to corroborate that view. Bin Laden is reported to have instructed his aides to kill him to prevent capture by the Northern Alliance or the Americans. He is also thought to have drawn up a "last testament" in the form of a videotape to be broadcast in the event of his death. In it, he instructs his followers to continue attacking US targets. One plan may be to draw in the Americans and the British to finish a job that the mujahideen, despite the $25 million reward (Rs 120 crore) and the $100 (Rs 4,800) a month being paid to their commanders by the Allies, may be unwilling to die doing. Says one senior British staff officer: "They desperately want us to commit more men and take some big hits. We aren't going to play their game." However, 40 Special Forces men have already been sent into Tora Bora and more are expected.

Bin Laden's options are undeniably limited. Even if he overcame the logistic difficulties of escaping Afghanistan, there are few places he could go. Wilder suggestions such as the Philippines or Chechnya can be discounted as impossibly impractical. Iraq is hugely unlikely. Bin Laden sees Saddam Hussein as an evil secularist and detests much of what he stands for.

WAR ON TERROR

LIKELY HAVENS Osama bin Laden: Somalia and Yemen are believed to be his best options. Mullah Omar: May be holed up in the mountains south of Khost. Ayman Al-Zawahiri: Believed to be heading for an East African or Yemeni port.

Instead, Somalia could be bin Laden's first choice. Ravaged by years of civil war, the East African country has almost no effective government and bin Laden's people know it well. In 1993 he sent operatives to help train the tribes which confronted the US military there, leaving 18 servicemen dead. Bin Laden's links there are still reported to be strong. Recently, the Bush Administration accused two Somali financial service networks of funnelling funds to Al Qaida, and ordered their assets frozen.

Yemen is also an option. Bin Laden's father, Mohammed, was born in the poverty-stricken province of Hadramaut and moved to Saudi Arabia, where Osama was born. While bin Laden's family has disowned him, he still has many supporters in his homeland, and has spent years building an Al Qaida network there. Letters from students of the terrorist camps bin Laden ran in Khost reveal that he had entrusted some of his best recruits with the task of setting up a cell based in the capital, Sanaa. Whether they were responsible for last year's attack on the USS Cole in Yemen is unknown.

The nightmare scenario facing the US is that bin Laden or his senior lieutenants escape to regroup and perpetuate the Al Qaida threat. The US is hoping to forestall that by closing down all destinations bin Laden might be tempted to escape to. Pressure is building up in Washington to hit at Iraq once the Taliban is subdued, Yemen has been threatened with the consequences of harbouring bin Laden, and the Pentagon has drawn up military plans for a strike against Somalia and Sudan, should any sign emerge of co-operation between their regimes and any group linked with Al Qaida. But to escape at all, bin Laden would almost certainly have to cross Pakistan and though he undoubtedly has friends within the ranks of the Pakistani Army, especially in the ISI spy agency, it is unlikely that they would risk their lives and the future of their institutions and nation to help him.

Even so, the US believes that a decapitated Al Qaida may still be extremely dangerous. Pentagon officials said last week that military intelligence indicated a wing of the outfit is preparing to re-group. They also maintain that a major attack in America-to have taken place in recent weeks-has narrowly been averted.

Sources say Al Qaida's most mercurial figure may have already slipped the net: Ayman al-Zawahiri, the Egyptian surgeon jailed but later released for his part in the successful plot to assassinate President Anwar Sadat. Al-Zawahiri, bin Laden's companion ever since the Saudi returned to Afghanistan from Sudan in 1996, is the ideologue of Al Qaida and one of the founders of Islamic Jihad in his home nation. US intelligence suggests that he may well have fled aboard a ship for an East African or Yemeni port, and is likely to set up a renovated Al Qaida cell in a host country. His family is believed to have died in a recent American missile strike. Other key Al Qaida figures-military chief Mohammed Atef and key financial man Ali Mahmood-have died, there are others who could take their place.

After all, experts on bin Laden's network say that more than 80 per cent of it exists outside Afghanistan. German specialists estimate that 70,000 foreign Muslims who have passed through the dozens of camps run by Al Qaida in eastern Afghanistan are now scattered across the world. In the wake of the American attacks, cells have been uncovered in Germany, France, Spain and the US. However, investigators have failed to track down key middlemen responsible for back-up and funding.

In Germany, where the conspiracy was hatched, the authorities have identified at least five Al Qaida members but have insufficient evidence to persuade prosecutors of their guilt. The classic cell structure operated by Al Qaida, where there is little if any contact between each unit, makes it almost impossible to penetrate. But even without their leader, these groups will continue to pose a threat for years to come. "Certainly, we don't expect the death or capture of Bin Laden to mark the end of this," said one American intelligence source. "In fact, we are expecting something pretty horrible here (in the US) precisely because of the developments in Afghanistan."

Nor is money likely to be a problem. The US-led assault on Afghanistan and the Taliban, who themselves were once supplied with huge sums by wealthy Gulf Arabs, is likely to lead to large donations for terrorist groups from disaffected rich Muslims all over the world.

In a hospital bed in the southern Pakistani border city of Quetta last week, a young Arab wounded by the Americans was full of defiance despite his injuries. "My life is dedicated to two things: defeating the West and martyrdom," he said. "I will not rest until I am successful." It is a pledge he may still be able to keep.