The Bush administration has moved to increase the pressure on the Taliban regime in Afgahanistan to hand over Mr Osama bin Laden.
Washington was responding to a dramatic reversal from the Taliban, which said for the first time that it is harbouring the suspected terrorist in Afghanistan. Senior administration officials called on the Taliban to hand over Mr bin Laden or face the consequences.
As speculation continued about the timing of a military response from the US, Mr Bush's Attorney General, Mr John Ashcroft, warned of the "likelihood" of further terrorist action and warned that US retaliation could increase this risk.
In a move seen as a major setback to any US plans for an airstrike against Afghanistan, Saudia Arabia said that it would not allow its airbases to be used by American military forces as part of an attack on any Arab or Muslim country. However senior anti-Taliban Afghan figures were quoted as expecting a US military strike within days.
The claim that the Taliban held Mr bin Laden came from the its ambassador to Pakistan, Mr Mullah Abdul Salam Zaeef. He said yesterday that Mr bin Laden was "at an unknown place for his safety" and that only security people knew about his whereabouts".
"Osama bin Laden is under our control," he said. Shortly after the September 11th attack on the World Trade Centre, the Taliban said it did not know of Mr bin Laden's whereabouts.
Mr Zaeef also said that Mr bin Laden had been given the edict from a council of religious elders asking him to leave the country, but had not responded to it.
"The ulema (council) recommendation was handed to him ... it has reached him," said Mullah Zaeef. "There has been no response."
However Washington responded impatiently to Mr Zaeef's comments. The White House chief of staff, Mr Andrew Card, said: "We've told the Taliban government what they should be doing. They've got to turn not only Osama bin Laden over but all of the operatives of the al Qaeda organisation. They've got to stop being a haven where terrorists can train" .
The Defence Secretary, Mr Don Rumsfeld, said on NBC's Meet the Press that he questions anything the Taliban says. Of the suggestion they are now holding bin Laden, he said, "Well, of course it was just a few days ago that they said they didn't know where he was. So I have no reason to believe anything a Taliban representative would say."
The Attorney General, Mr Ashcroft, meanwhile, warned of "substantial risks" of further terrorist activity. These risks could increase as the US retaliates for the attacks, he warned.
"We believe there are others who may be in the country who would have plans," Mr Ashcroft said on CBS Face The Nation. "There is a very serious threat of additional problems now," he said.
The British Prime Minister, Mr Tony Blair, said yesterday he had seen "incontrovertible" evidence linking Osama bin Laden to the attacks on the United States.
Conflicting reports about the status, or existence in fact, of Afghanistani refugees crowded at the Pakistan border continued.
Last week there were reports of some 10,000 refugees huddled near the Chaman border.
Yesterday the UNHCR spokesman, Mr Rupert Colville, confirmed that the refugees had "evaporated".
UNHCR observers noted that the crowd had dwindled significantly, leading to speculation that 10 days in the unsheltered area without tents of water, combined with confidence that a US attack was not imminent, and word of food supplies re-entering the country, had driven the refugees back to their homes.
Meanwhile a convoy of emergency food aid was on its way from Pakistan toward hungry and isolated people in Afghanistan.
UN aid shipments left for the war-ravaged country on Saturday. This was the first time any food supplies have been sent into Afghanistan since the September 11th attacks on the United States.