PASSENGERS flying to the United States will have to undergo upgraded security checks on carry-on luggage at Bermuda International Airport following the discovery of a plot to blow up transatlantic airliners.

As a result, those flying to the US have been warned to arrive at the airport two-and-a-half hours before departure time.

The new procedure, which came into effect yesterday, bars passengers to the US from carrying any liquids in their hand luggage.

But airport general manager Jim Howes said yesterday that the more stringent measures did not apply to those flying to the UK or Canada.

It is believed that the terrorists planned to smuggle explosives disguised as toiletries and beverages, as well as detonators, onto the planes in carry-on luggage. Hundreds of flights were cancelled at London's Heathrow and Gatwick Airports yesterday as the UK raised the threat alert to maximum levels.

However, British Airways' daily flight from Gatwick to Bermuda went ahead with only a short delay and touched down on the island less than half an hour later than its scheduled 6.20 p.m. arrival time.

The US Homeland Security Department raised its threat level for flights from the UK, to "severe" or "red", the highest in a five-step scale. The security level for flights from Bermuda and other international locations to the US, was raised to "orange", or "high", the second level.

Unconfirmed reports said anywhere from six to ten airliners had been targeted in a conspiracy which British police said was meant to cause "mass murder on an unimaginable scale".

UK officers said they believed they had "disrupted" the plan after the arrest of 24 people in the London and Birmingham areas early yesterday morning. And Britain's Home Secretary John Reid said he was confident that the "main players" in the terror conspiracy had been detained.

Transport and Tourism Minister Ewart Brown was himself caught up in the chaos at London's airports yesterday. Dr. Brown said his holiday plans had been disrupted by a cancelled flight. He returned to his hotel in London and was hoping to continue his journey tomorrow.

Dr. Brown referred us to Mr. Howes for comment on the beefed-up security measures.

Mr. Howes said: "The US Department of Homeland Security has announced that the threat level is now 'orange' for international airline flights to the US. This will require additional screening measures at Bermuda International Airport effective immediately and enhanced inspection of carry-on items for flights to the US.

"Specifically, no liquids may be carried by passengers on board flights to the US. This ban includes gels, beverages, toothpaste, lotions, and liquor. Such items must be placed in checked baggage. Only prescription drugs and baby formula will be permitted to be taken aboard US-bound airplanes by passengers.

"We recommend that all US-bound passengers arrive at the airport two-and-a-half hours ahead of their scheduled departure time. If in doubt as to allowed items, or the status of flights, passengers should contact the airline."

US Homeland Security Secretary Michael Chertoff said the plot was in the final stages of planning before execution.

"The terrorists planned to carry the components of the bombs, including liquid explosive ingredients and detonating devices, disguised as beverages, electronic devices or other common objects," he said.

Departure halls were jammed with people, waiting as airlines cancelled flights and trying to sort out their bags as hand luggage and liquids were banned from flights and passengers with babies were made to publicly taste their food.

British security sources said they had been watching the suspects for eight months. They did not rule out an al Qaeda link, but played down direct involvement by the militant group.

British authorities declined to confirm the nationalities of those arrested, but US authorities later revealed that all the detainees were British citizens.

British police also said the plot had "global dimensions" and that police were co-operating with foreign agencies. And the Foreign Office later said some arrests had been made in Pakistan in connection with the plot.

Mr. Chertoff said US carriers were targeted. One US official, speaking on condition of anonymity, said Continental Airlines, United Airlines and American Airlines flights were the focus.