British police thwart aircraft bomb plot

British authorities thwarted a terrorist plot to blow up several aircraft mid-flight between the United States and Britain using explosives smuggled in hand luggage, officials said Thursday.

Britain's Home Secretary John Reid said the alleged plot was "significant" and that terrorists aimed to "bring down a number of aircraft through mid-flight explosions, causing a considerable loss of life."

Police arrested a number of people overnight in London after a major covert counterterrorism operation that had lasted several months, but did not immediately say how many.

The US government responded by raising its threat assessment to the highest level for commercial flights from Britain to the United States early Thursday.

"We believe that these arrests (in London) have significantly disrupted the threat, but we cannot be sure that the threat has been entirely eliminated or the plot completely thwarted," said US Homeland Security Secretary Michael Chertoff.

Chertoff added in the statement there was no indication of current plots within the US.

Heathrow Airport, Thursday (Photo: AP)

Britain's national threat level was also raised to critical — a warning level that indicates the likelihood of an imminent terrorist attack. The threat rating was posted on the Web site of Britain's MI5 — the British domestic spy agency.

Heathrow airport, the busiest in Europe, was closed to most European flights Thursday morning following

the heightened terrorist alert, officials said. The block on incoming traffic applied to flights of three

hours or less, affecting most of the incoming traffic from Europe, an airport spokesman said on condition of anonymity in line with airport policy.

Congestion was building up rapidly at the airport as authorities enforced strict new regulations banning most hand baggage.

Passengers panic

Prime Minister Tony Blair, vacationing in the Caribbean, had briefed President Bush on the situation overnight, Blair's office said.

The British Department of Transport advised all passengers that they would not be permitted to carry any hand baggage on board any aircraft departing from any airport in the country. Passengers faced delays as tighter security was hastily enforced at the country's airports and additional measures were put in place for all flights.

"I'm terrified really, I'm really scared," said Sarah Challiner, 20, who was waiting to board a flight from Manchester's airport.

Hannah Pillinger, 24, seemed less concerned by the announcement. "Eight hours without an iPod, that's the most inconvenient thing," she said, waiting at the Manchester airport.

London's Heathrow airport was the departure point for a devastating terrorist attack on a Pan Am airplane on Dec. 21, 1988. The blast over Lockerbie, Scotland, killed all 259 people aboard Pan Am Flight 103 and 11 people on the ground.

The explosive was hidden in a portable radio which was hidden in checked baggage.

A Scottish court convicted Libyan intelligence agent Abdel Basset Ali al-Megrahi of the bombing in 2001 and sentenced him to life imprisonment. A second Libyan was acquitted.

In 2003, Libya officially accepted responsibility for the attack and agreed to pay relatives of each bombing victim at least USD 5 million.