The Metropolitan Police say the man shot dead by officers at Stockwell tube station in London yesterday was "directly linked" to their ongoing and expanding anti-terrorist operation. Frank Millar, London Editor, reports.
However, amid conflicting reports last night, it was not clear whether the Asian man, who had been under surveillance, was one of the four suspects in Thursday's unsuccessful attempt to bomb London's transport network.
As police released CCTV images of the four men wanted for questioning about the attempt to cause explosions on three Underground trains and a bus, Muslim leaders expressed concern about a possible "shoot-to-kill" policy.
Eyewitness Mark Whitby described scenes of "absolute mayhem" inside Stockwell station around 10am as plain-clothes officers pushed the man through the open doors of his carriage and onto the floor before one of them "unloaded five shots into him".
Mr Whitby said the man was shot through the head. "I saw the gun being fired five times into the guy - he is dead," he assured the BBC as an air of disbelief attended one of the most extraordinary episodes in the history of British policing.
Other witnesses described more than 20 officers piling into the station, amid speculation that a surveillance operation was forced to a lethal conclusion with officers fearing their target might be a suicide bomber.
Metropolitan Police Commissioner Sir Ian Blair said "any death is regrettable" while confirming his understanding that "the man was challenged and refused to obey police instructions". He also appealed to "all communities" to ignore "rumours sweeping London" and "listen to the facts as they emerge".
The Muslim Council of Britain expressed concern about the possible operation of a shoot-to-kill policy.
Spokesman Inayat Bunglawala said: "There may well be reasons why the police felt it necessary to unload five shots into the man and shoot him dead, but they need to make those reasons clear.
"It is vital the police give a statement about what occurred and explain why the man was shot dead," Mr Bunglawala added.
However London mayor Ken Livingstone praised the swift police action and said that, with the capital on the alert after two sets of terrorist attacks, decisive action or even a shoot-to-kill policy might be necessary.
"If you are dealing with someone who might be a suicide bomber - if they remain conscious, they could trigger plastic explosives or whatever device is on them and therefore overwhelmingly in these circumstances it is going to be a shoot-to-kill policy," he said.
"I think we are making people safer by better intelligence and a better use of our resources. With each of these attacks, we have responded more rapidly and effectively and I'm glad it went as well as it did today."
The mayor's comments fuelled the widespread assumption that the manhunt which led to yesterday's fatal shooting was "intelligence led". There were unconfirmed reports last night that the linkage to Thursday's bombing mission might have been found in documents left inside the partially exploded devices.
All four suspects were officially "on the run" last night after police issued their images and appealed for information about their whereabouts, while warning the public that the men were dangerous and should not be approached.
Hundreds of armed officers were deployed in operations across the capital during a day of rapid and shocking developments, which again brought security alerts, widespread travel disruption on rail lines and roads, and another night of frustration and delays for Londoners returning from work.
Police used tear gas during a raid on one address in west London, and a man who was arrested at a house in Stockwell, was last night being held under the Terrorism Act at Paddington Green station.
Another man was arrested in Birmingham, where two suitcases were being dealt with by explosives officers.
Commissioner Blair described the ongoing operation as "the biggest operational challenge ever faced by the Metropolitan Police service.