The early indications from today’s foiled plot to bomb planes out of London Heathrow Airport are that some of the suspects are Pakistani Brits. It’s still very early, however, and much info has yet to come out.

A major terrorist plot to commit mass murder on an unimaginable scale by exploding up to nine aircraft in mid-flight between Britain and America has been thwarted, Scotland Yard announced this morning.

So far 21 suspects - believed to be British citizens, many of Pakistani origin - have been arrested in overnight raids in London, the Thames Valley and Birmingham… The suspects in custody are believed all to be British citizens, many of them of Pakistani origin. [Link]

He refused to comment on the people in custody but hinted strongly that British Islamists were behind the alleged plot, as Britain’s domestic Press Association news agency said those arrested were of Pakistani origin.

The officer instead said police had informed community leaders — a shorthand often used in Britain to refer to people of minority faiths and ethnic groups, in particular the Muslim population — about the operation. [Link]

Domestic news agency Press Association quoting unnamed senior police sources said a majority of those arrested were believed to be of Pakistani origin but most, if not all, were British. [Link]

Details of the alleged plot:

A U.S. intelligence official said authorities believe the plot involved sophisticated liquid explosives that were to have been carried on to aircraft, with battery triggers possibly stored in alarm clocks, laptop computers and calculators… A U.S. official who asked not to be further identified said United Airlines, Continental Airlines and American Airlines had been specifically targeted for attack. [Link]

British authorities said the threat involved terrorists who aimed to smuggle liquid explosive material aboard airplanes in hand baggage, including timers and detonators that could be assembled in flight. In July 2005, terrorists attacked London’s subway and bus system with bombs made of acetone and peroxide mixed in plastic containers…

Chertoff said the plot, which he described as “sophisticated,” was indicative of an al-Qaeda operation… Chertoff said the attackers planned to carry explosive material and detonation components on planes “disguised as beverages, electronic devices and other common objects.” [Link]