Police chiefs are completely rewriting their official manual on how to deal with terrorists in the wake of the 7 July atrocities.
This paper has learnt that all Britain's chief constables met at a "terror summit" last Tuesday at Scotland Yard to draw up national strategies.
Current procedures are based on the experience of dealing with the IRA and do not give advice to officers on dealing with suicide bombers.
The Association of Chief Police Officers has circulated a memo to all forces urging them to revise their procedures on evacuating civilians and dealing with suspects planning an attack.
A senior anti-terror police source said: "We are familiar with how to deal with Irish terror and bomb explosions. You get a warning and go through fixed procedures, evacuation, you know not to use a mobile phone. All that still holds good, but it's going to be redundant when you look at what you have experienced in London."
Anti-terror officers have dismissed as "nonsense" that the four bombers may have been duped into carrying out the attacks in the belief they would be able to escape before the devices were detonated.
A Metropolitan Police source said: "If they were duped, the person on the bus would have known his three friends had been killed [and would have got away]."
Forensic expertsare examining the hard discs of computers seized in raids in Leeds and Luton last week.
Last night, the Met formally confirmed the identities of the third and fourth bombers: Mohammed Sidique Khan, 30, who died at Edgware Road and Germaine Lindsay, 19, was blown up between King's Cross and Russell Square.
Yesterday, forensic teams conducted detailed searches of three of the 10 addresses in West Yorkshire and one address in Aylesbury, Buckinghamshire, raided by police.
A 29-year-old man arrested last week under anti-terror laws was still being questioned at Paddington Green police station.
So far, officers have taken more than 800 witness statements and received 3,500 calls from the public on the anti-terrorist hotline. More than 6,000 CCTV tapes are being analysed.
Deputy Assistant Commissioner Peter Clarke, the head of the Anti-Terrorist Branch, thanked the public for coming forward but added: "We still need to find out more about these four men and their movements, both on the morning of the bombings, and in the days and weeks beforehand.
"We are this evening releasing a CCTV image showing the four men at Luton train station at approximately 7.20am. We know they travelled together on a Thameslink train to King's Cross.
"Did you see these four men? Did you see them together in the days before the attack? Do you have information on any of these men?"
You can contact police on the confidential Anti-Terrorist Hotline on 0800 789 321, or electronically online via www.police.ukReuse content