Way to F***ing go Scottland Yard!
cnn LONDON, England (CNN) -- British police say they have arrested 21 people in connection with a terrorist plot to blow up aircraft flying from the United Kingdom to the United States.
The plot was "intended to be mass murder on an unimaginable scale," Metropolitan Police Deputy Commissioner Paul Stephenson said. The UK's threat warning level has been raised to "critical" -- meaning "an attack is expected imminently."
London's Heathrow airport was closed to most European flights Thursday morning, causing chaos for thousands of travelers. The closure to incoming traffic at the world's busiest international airport applied to flights of three hours or less, a spokesman said. (Full story)
The plot involved hiding masked liquid explosives in carry-on luggage, a U.S. government official told CNN. A U.S. administration official said United, Continental and American airlines were believed to be among airlines targeted by the plot.
British and U.S. security agencies quickly moved to limit carry-on items, causing extended delays at airport security checkpoints. The British Airports Authority said no hand luggage would be allowed onto planes leaving UK airports. (Full story)
Stephenson said the plot involved a plan to blow up passenger jets flying between the United Kingdom and the United States.
He said 21 people were arrested by London, Birmingham and Thames Valley police overnight in an ongoing operation.
"This is about people who are desperate ... who want to do things that no right-minded citizen of this country or any other country would want to tolerate," Stephenson said.
The arrests were the result of a "covert counter-terrorist operation," police said. "It is believed that the aim was to detonate explosive devices smuggled on board the aircraft in hand luggage."
Britain's Home Secretary John Reid said: "We are doing everything possible to disrupt any other terrorist activity. This will mean major disruptions from all UK airports."
In the United States, the Department of Homeland Security raised the terror threat to the highest level of "severe," or red, for commercial flights originating in the United Kingdom bound for the United States.
In addition, the threat level has been raised to "high," or orange for all commercial flights operating in or coming to the United States, a DHS statement said.
"Due to the nature of the threat revealed by this investigation, we are prohibiting any liquids, including beverages, hair gels, and lotions from being carried on the airplane," the statement said."
A U.S. Transporation Safety Adminstration official said travelers should show up at least two hours ahead of their flights and bring plenty of patience. According to the DHS, there is no indication the plot involved American counterparts.
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.
