LONDON (CNN) -- British police have disrupted what they believe was a major terrorist plot to blow up aircraft in flight, likely between the United Kingdom and the United States, a statement from Scotland Yard said Thursday.
"It is believed that the aim was to detonate explosive devices smuggled on board the aircraft in hand luggage. It is believed that the attacks would have been particularly targeted at flights from the UK to the USA," the statement said.
Arrests were made overnight in London by the Metropolitan Police Department's anti-terrorist branch and security service.
"Today's arrests are the culmination of a major covert counter-terrorist operation lasting several months," Scotland Yard said.
"We would like to reassure the public that this operation was carried out with public safety uppermost in our minds," the statement said.
"This is a major operation which inevitably will be lengthy and complex. We will provide further information as soon as possible."
The British Airport Authority said additional air travel security measures have been implemented in light of developments.
"All passengers must be hand searched, and their footwear and all the items they are carrying must be x-ray screened," a BAA statement said.
The alleged terror plot comes more than five years after Briton Richard Reid attempted to detonate explosives hidden in his sneakers on an American Airlines flight from Paris to Miami in December 2001, only a few months after the September 11, 2001 attacks in New York and Washington.
Passengers thwarted his plan, and the plane landed safely in Boston. Reid pleaded guilty to terrorism charges in October 2002 and is serving a life sentence at the nation's super-maximum security prison in Florence, Colorado.
