Britons foil plot to bomb airplanes

LONDON – Authorities in London thwarted a terrorist plot to blow up aircraft midflight between Britain and the U.S. using explosives smuggled in hand luggage, police said today.

Britain’s Home Secretary John Reid deemed the alleged plot significant and said it was designed to “bring down a number of aircraft through midflight explosions, causing a considerable loss of life.”

The United States government has raised its security threat level in response to the plot.

Authorities arrested a number of people overnight in London after a covert counterterrorist operation lasting several months, police said in a statement. The BBC reported on its Web site that about 18 people were arrested.

The national threat level was raised to critical – a warning level that indicates the likelihood of an imminent terrorist attack. The threat rating – based on a U.S. Department of Homeland Security’s model – was posted on the Web site of Britain’s MI5 – the British domestic spy agency.

Security at the country’s airports was increased and additional measures were put in place for all flights.

British Airways 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.