SOURCE:
Bangkok Post Breaking News
London (dpa) - British authorities have foiled a "very significant" terrorist plot aimed at bringing down a "number of aircraft through mid-air explosions with a considerable loss of life," Home Secretary John Reid said Thursday.
The minister announced that the country had, for the first time ever, been placed the highest level of alert. The level "critical" meant that an "attack was imminent."
One security expert said this could mean that a "plot was actually under way."
The BBC quoted security sources as saying that British-born terror suspects were believed to have been involved in plotting "near- simultaneous" attacks on three aircraft over the mid-Atlantic.
Reid said the security measures were "cautionary" and were expected to cause major disruptions at airports. Scenes at Heathrow and Gatwick airports in London were described as "chaotic."
Earlier police said 18 people have been arrested in an anti- terrorist operation in the London area.
Security sources said police had broken up a group that had been "watched for a while" and that had "put together the material" for an attack.
The BBC's security correspondent said a "wave of attacks" were planned.
The plan was believed to have been to attack aircraft travelling from Britain to the US with devices smuggled on board in hand luggage.
No hand luggage can be taken on board, with only travel documents and essential medicines allowed on in see-through bags.
All cabin baggage must be processed as hold baggage and carried in the hold of passenger aircraft departing UK airports.
All passengers were checked by hand, and their footwear was investigated, police said.