..and one day after their last fumbled (and failed) attempt to do the same again.
http://news.bbc.co.uk/1/hi/uk/4706787.stm
Does this change anything? Does it mean the police are closer to finding the people responsible for yesterday's failed attacks, and therefore the attacks of two weeks ago?
http://news.bbc.co.uk/1/hi/uk/4706787.stm
Man shot dead by police on Tube
Stockwell Tube station
Police have cordoned off a 200-metre area around the station
A man has been shot dead by police at Stockwell Tube station in south London, as officers hunt four bombing suspects.
Met Police Commissioner Sir Ian Blair said officers fired after the man was challenged and refused to obey police.
The incident was "directly linked to the ongoing and expanding anti-terrorist operation", he said.
BBC crime correspondent Neil Bennett said the man shot dead was not thought to be one of four bomb suspects shown in CCTV images released by police.
Officers hope the CCTV footage will help them trace the four people they say tried to set off devices on Thursday at Oval, Warren Street, Shepherd's Bush stations and on a bus in Shoreditch in east London.
They pushed him to the floor, bundled on top of him and unloaded five shots into him
Witness Mark Whitby
'They unloaded five shots'
Shooting watershed for UK
Stockwell in graphics
Police have yet to release details of the identity of the man shot dead at about 1000 BST in Stockwell.
Sir Ian told a press conference: "I need to make clear that any death is deeply regrettable but as I understand the situation the man was challenged and refused to obey police instructions."
Stockwell passenger Mark Whitby told BBC News he had seen a man of Asian appearance shot five times by "plain-clothes police officers".
"One of them was carrying a black handgun - it looked like an automatic - they pushed him to the floor, bundled on top of him and unloaded five shots into him," he said.
Police have cordoned off a 200-metre area around Stockwell station. Passengers were evacuated from the station, which is on the Northern Line and Victoria Line.
Teams of forensic officers are working inside the station, and police helicopters are hovering overhead.
Services on the Victoria and Northern lines were suspended following a request by the police.
BBC Home affairs correspondent Margaret Gilmore said officers had challenged a known suspect they had been following.
"He ran, they followed him. They say they gave him a warning, they then shot him.
"They brought in the air ambulance. They did everything they can to revive him. He died at the scene."
Police had warned they would shoot to kill if they believed somebody to be a threat, she added.
It's vital the police give a statement about what occurred and explain why the man was shot dead
Muslim Council of Britain
Will police now shoot to kill?
The Muslim Council of Britain said Muslims were concerned about a possible "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's vital the police give a statement about what occurred and explain why the man was shot dead."
Another passenger on the train, Anthony Larkin, told BBC News the man appeared to be wearing a "bomb belt with wires coming out".
The man burst in through the door to my right and grabbed hold of the pole and a person by the glass partition near the door
Passenger Dan Copeland
Stockwell left in shock
Londoner Dan Copeland was in the carriage in which the man was shot.
He told BBC News: "We were sitting for a few minutes on the platform, then we heard shouting from the concourse between the two platforms.
"Then the man burst in through the door to my right and grabbed hold of the pole and a person by the glass partition near the door, diagonally opposite me.
"An officer jumped on the door to my left and screamed, 'Everybody out!'
"People just froze in their seats cowering for a few seconds and then leapt up.
"As I turned out the door onto the platform, I heard four dull bangs.
"I ran past an armed officer who was standing on the platform and ran up the stairs."
Does this change anything? Does it mean the police are closer to finding the people responsible for yesterday's failed attacks, and therefore the attacks of two weeks ago?