A total of 21 people have been arrested in connection with a suspected terrorist plot to blow up aircraft in mid-air, Scotland Yard said today.
The majority of the arrests were carried out overnight in London, with some in the Thames Valley and in Birmingham, Deputy Commissioner Paul Stephenson said.
Mr Stephenson said the plot, which was intended to bring down a number of aircraft through mid-flight explosions, was designed to cause "untold death and destruction".
He said: "This was intended to be mass murder on an unimaginable scale."
Searches were ongoing at a number of addresses, he added.
Sources indicated that the majority if not all of those arrested were British.