TRAVELLERS to the United States are being urged to allow longer for security at airports in the wake of the failed Detroit airliner bomb attempt.

In the immediate aftermath of the Delta/NorthWest delays of up to three and a half hours were reported at UK airports while urgent investigations were continuing as to how the passenger from Nigeria - known to both US and British authorities - was able to take explosives on board an Airbus from Amsterdam carrying 278 passengers.

Passengers at Belfast International Airport and other UK airports are facing tighter security in the wake of the alleged Detroit bombing.

A Spokesperson for the Airport confirmed it had tightening security for passengers on all Continental Airlines flights to the US. Continental operates a daily service from Belfast to New York (Newark).

Passengers using the Continental service are now being restricted to just one piece of hand luggage instead of two.

"Following the Delta Airlines' incident on Christmas Day, the US Transportation Security Authority, TSA, has introduced addditional secruity measures fro those passengers travelling on US-bound flights," the Spokesperson said.

Passengers travelling from the UK to the US are being warned to arrive early and expect extra bag checks and vigorious body pat-down searches.

There will also be a strict enforcement of a limit of one item of hand baggage.

A BAA spokesperson told ABTN: "The standard security procedures at the airports remain the same for all flights.

But for US-bound passengers, "the issue is that the TSA (US Transport Security Administration) have insisted that airlines flying to the US carry out a secondary search on all passengers at the gate," said BAA.

The secondary search involves hand held metal detectors and pat down searches, added BAA.

Wrapped presents in hand luggage must be unwrapped and an hour before landing in the US, there is no access to toilets on board the aircraft, no moving from your seat, no access to hand luggage and no items allowed on your lap.

The foiled bomber Umar Farouk Abdulmutallab is accused of trying to ignite explosives sewn inside his underwear on Northwest Flight 253 from Amsterdam as it approached Detroit on Christmas day. He was overpowered by passengers and crew.

The failed bomb plot may lead to increased use of full body scanners and Northern Ireland airports are said to be on standby to introduce ful body scanning as soon as the British Government give the go ahead.

These hyper-sensitive X-ray machines create an image of the subject's naked body on the security screen, which shows up anything strapped to the subject's body, such as explosives.

The measure has been demanded by prime minister Gordon Brown in the wake of the foiled bombing.

US President Barack Obama has asked security officials for a plan to strengthen aviation screening technology and procedures following the incident, Reuters reported, which may lead to permanent changes in airport security measures.

Increased security covering travellers from 14 countries to the US has also been introduced and some passengers have also experienced bans on the use of electronic equipment.

The extra security measures are yet another blow to the worldwide airline industry as it struggles to get back to profitability after the recession.

If you are unsure about any aspect of airport security when planning a trip to the US, contact your airline or travel agent in advance of your date of travel