Despite a $5m reward and his inclusion on the FBI's most wanted list, the alleged terrorist who has denied any part in the attacks remains at large with unconfirmed reports saying that he has set up a new base in Afghanistan, near to the Zhawar Kili "terrorist training camps" hit by US cruise missiles in August 1998.

Click here to see a map of Osama bin Laden's movements.

Afghanistan's Islamic Taleban movement continues to shelter Osama bin Laden, saying that he remains a "guest of the Afghan people".

More attacks? Taleban fears Washington is preparing

Washington alleges that Osama bin Laden heads a complex terrorist network funded by his personal fortune, secretly channelled through Middle East banks.

But Paul Wilkinson, professor of International Relations at Scotland's St Andrews University, said that the US government still does not have any hard evidence against Mr bin Laden.

"What we have is a number of very serious allegations and undoubtedly a lot of evidence that bin Laden has made threats to attack United States targets," said Prof Wilkinson.

Reward: $5m for information leading to arrest

"There's no doubt about his determination and fanaticism, his opposition to the United States presence and its policies in the Middle East.

"But we still do not have proof that he was actually the mastermind behind the embassy bombings."

The US State Department's co-ordinator on counter-terrorism, Mike Sheehan, insisted that the evidence against Mr bin Laden is convincing.

"He and 16 others have been charged in New York and in London, regarding this case," he told the BBC.

"I have been up to New York to see the members of our Justice Division as well as the FBI which investigated this case. It is a very impressive case."

Irrespective of whether he is innocent or guilty, the cruise missile strikes and Washington's determination to hunt him down has boosted the profile of the dissident.

Peter Marsden, a writer on the Taleban, said that many Islamists regarded Mr bin Laden as a hero.

"He fought alongside the Mujaheddin during the Soviet period and earned himself an enormous amount of credibility as a result," he said.

"The Jamiatul-Ulama-Islami party in Pakistan recently threatened to kill Americans in Pakistan if the US launched further US air strikes on Afghanistan, and particularly to try and kill Osama bin Laden."

The US is continuing to pressure the Taleban into expelling Mr bin Laden but has rejected suggestions of a deal which would see him handed over in exchange for international recognition for the de facto controllers of most of Afghanistan.

"There's two roads that we can go down in our relationship with the Taleban," said Mike Sheehan.

"One is where they would turn him over to justice and we would move forward.

"If they continue to provide safe haven, it is going to be a much more difficult and more pressure and continued sanctions."

Whereabouts unknown

In recent weeks there has been increased speculation about Mr bin Laden's exact intentions.

Kandulah: Reported hide-out for Osama bin Laden

Earlier in the year, he was reported to be staying in the south-eastern Afghan city of Kandahar before disappearing once more.

A journalist with the UK's Observer newspaper reported that the dissident has set up a new base outside the eastern city of Jalalabad near to the border with Pakistan.

There have been reports of at least two attempts against his life but his efforts to keep on the move are said to be hampered by his poor health.

To add to the confusion, the Pakistan-based Afghan Islamic Press reported that the dissident had decided to leave Afghanistan "because of expected attacks from the United States" - a report that some Western analysts suggested was a Taleban attempt to prevent a second US missile strike.

Until he does surface, the game of international cat and mouse will continue.

But leaders in the US say that they want Osama bin Laden to be sure of one thing: They have a very long memory when it comes to terrorism crimes against America - and he remains the prime suspect.