AS AIRLINE delays mounted because of terrorism jitters, an Arabic-language television channel yesterday aired a new audiotape in which a man claiming to be Osama bin Laden urged Muslims to step up the armed struggle against the West.

The message broadcast on al-Jazeera referred specifically to the December 14 capture of ousted Iraqi president Saddam Hussein, suggesting the tape had been recorded recently. A CIA spokesman, who asked not to be named, said it was likely to take a day or so before it could be determined whether the recording was real.

If confirmed as authentic, the tape would be the first from the al Qaeda leader since the Bush administration raised the national threat level to orange on Dec. 21, indicating a high risk of terrorist attack. Terrorism experts have noted that bin Laden often times his pronouncements to coincide with a new spate of attacks.

US intelligence officials concluded that an alleged bin Laden tape aired last month by another Arab television station, al-Arabiya, was a rebroadcast of earlier material. In the new 47-minute tape, the speaker refers to several time-specific events, including Hussein?s capture and a December 1 ?Geneva accord? between unofficial Israeli and Palestinian negotiators outlining a possible Middle East peace deal.

The speaker sharply attacks Arab governments for failing to resist US policies in the Middle East and for ?stopping financial aid? to the families of Palestinian suicide bombers. He calls on Muslims to continue jihad, or holy war, ?to check the conspiracies that are hatched against the Islamic nation.?

Ibrahim Hilal, al-Jazeera?s editor in chief, told the Associated Press he is confident the tape is authentic. ?It is bin Laden?s superb and special Arabic language that is very hard to emulate,? he said.

Western governments, meanwhile, remained on high alert against terrorist attacks, with particular attention being paid to flights into Washington and Los Angeles. A total of 13 flights on British Airways, Air France and Aeromexico have been canceled or delayed since New Year?s Eve because of security fears.

?The terrorist threat is real right around the world at the present time,? British Prime Minister Tony Blair told reporters as he flew back from a brief visit to British troops in Iraq. ?Nobody is immune from it; you have to remain vigilant.?

Takeoff for British Airways Flight 223 from London?s Heathrow Airport to Dulles International Airport was delayed for the second straight day yesterday as US authorities cross-referenced the names of the 241 passengers with a terrorist watch list, said airline spokesman John Lampl. The same flight was canceled Thursday and Friday after intelligence intercepts suggested it might be the target of a terrorist attack.

British Transport Secretary Alistair Darling told the BBC that the decision to delay or cancel the flights was justified based on intelligence warnings. ?We are going to have to get used to increased security at airports,? Darling said. ?From time to time that will be noticeable, and at other times maybe things will be going on behind the scenes.?

US officials confirmed a report in Newsweek magazine that the FBI had demanded that hotel owners in Las Vegas provide names of everyone who booked rooms over the New Year?s holiday so they could be checked against a master list of suspected terrorists. A senior law enforcement official said the FBI used both administrative subpoenas and more informal national security letters to extract the information.

Las Vegas is one of several cities that have been on high alert because of intelligence information suggesting it could be the target of a new attack.

Justice Department spokesman Mark Corallo declined to comment on any specific case, but said: ?We are going to commit all available legal resources to protect the American people from a terrorist attack.?

The purported bin Laden audiotape described the US-led occupation of Iraq as the beginning of an American ?occupation? of Persian Gulf states for their oil. Western intelligence experts believe the al Qaeda leader is hiding in the mountainous border regions of southern Afghanistan and Pakistan, after escaping from US bomb attacks on his Tora Bora hideout in December 2001.

British Foreign Secretary Jack Straw said on Monday he assumed the voice on an audiotape aired on Sunday purporting to be Osama bin Laden was indeed that of the Saudi-born al Qaeda leader.

?Let?s assume that it was him,? Straw told BBC Radio. Asked if that was a safe assumption, Straw said: ?Yes.?

?There is no question that the al Qaeda organisation and its networks are still around, that?s palpable, and so far as we know Osama bin Laden is still alive,? Straw added.

The Arabic television channel Al Jazeera aired a tape on Sunday purporting to be from bin Laden in which he mentioned last month?s arrest of ousted Iraqi President Saddam Hussein by US troops.

Straw, however, said he had no confirmation the voice on the tape was that of bin Laden. ?Searching for him (bin Laden) remains a key issue,? Straw said.

Washington believes bin Laden masterminded the September 11, 2001, attacks on the United States. US forces began bombing Afghanistan the following month to drive out the Taliban, which harboured bin Laden and al Qaeda. Since then, the al Qaeda leader?s whereabouts have been unknown.

Michael Dobbs