Bush's demands to Taleban:

Hand over al-Qaida leaders to US Release "unjustly imprisoned" foreign nationals Close terrorist training camps and allow US inspection

Referring to indictments issued against Bin Laden before last week's attacks, Mr Powell said there was sufficient evidence for a trial.

The alternative, Mr Powell said, was a military campaign, but he said the action to be taken had yet to be decided.

Bin Laden's whereabouts are unknown, he said.

The attacks, which killed more than 6,000 people, have prompted the US to deploy troops and extra warplanes to within striking distance of Afghanistan, whose Taleban leaders have refused to hand over Bin Laden.

President George W Bush has said that Afghanistan must expel all suspects immediately or "share in their fate".

Our position is that if America has evidence and proof, they should produce it

Abdul Salam Zaeef Taleban ambassador to Pakistan

The US administration has rejected Taleban calls for proof that Bin Laden was responsible for the suicide attacks on New York and Washington.

The Taleban ambassador to Pakistan has said Bin Laden will never be handed over - he said such a move would be an "insult to Islam".

But there have been more expressions of support for the US campaign.

Russia offered to share intelligence information, while Chinese Foreign Minister Tang Jiaxuan said Beijing and Washington would continue co-operation against terrorism begun before the attacks.

In other developments:

• An opinion poll conducted after Mr Bush's speech to Congress on Thursday shows 90% of Americans support military action against those responsible for the attacks

  Many in Pakistan remain opposed to US action against Afghanistan

• The number of missing from the World Trade Center attack in New York rises to 6,333. Mayor Rudolph Giuliani says it could take at least six months to clear the wreckage
• Four die during pro-Taleban demonstrations in the Pakistani city of Karachi
• Three men and a woman are arrested in Britain in connection with the attacks
• The post-attack crisis and fears of a global recession push down share indexes, with losses on European markets, and in New York
• EU heads of state meeting in Brussels say US retaliation would be legitimate and agree to a Europe-wide search and arrest warrant.

Bush: US "awakened to danger"

But he said that the war would last for years and may never reach an end.

"It is a campaign that will probably continue for as long as I can imagine," he said.

"You will always have to have police and intelligence organisations working this, for as long as there are people willing to take this kind of risk and cause this kind of damage."

In an address to both houses of Congress on Thursday evening, Mr Bush said the US had been "awakened to danger" and "called to defend freedom".

In his address, Mr Bush carefully explained who Washington thinks carried out the attacks, and how the government was planning to respond.

Humanitarian crisis

Aid agencies are gearing up to prevent a humanitarian disaster as thousands of Afghans flee their country in fear of US military action.

The agencies say some three million Afghans depend on food aid.

The grim work at the World Trade Center could go on for six months

Afghans are pouring out of the cities, heading for villages or the borders. The UK-based Oxfam organisation has warned of a looming "catastrophe" and wants aid resumed to prevent refugees from besieging Afghanistan's borders.

The main supplier of food aid, the World Food Programme, has stopped all transport of wheat into and around the country.

And there are reports of a breakdown of law and order in the capital Kabul and other cities, with food being looted.

Substantial aid is going to Pakistan, the haven for more than two million Afghan refugees even before the current influx.