Police have released a CCTV image of the four London bombers as they set out from Luton on their bombing mission.
They have also confirmed the names of all four men for the first time.
Mohammad Sidique Khan, 30, Germaine Lindsay, 19, Hasib Hussain, 18, and Shehzad Tanweer, 22, were pictured in Luton at 0720 BST on Thursday 7 July.
Three bombs exploded on the London underground at 0850 BST, and one on a bus at 0947. Fifty-five people died, including the four bombers.
The picture was released in an attempt to find out more about their final movements.
Peter Clarke, head of the Anti-Terrorist Branch, said: "The investigation continues on many fronts, but we have been very grateful for the contribution made by the public in response to our previous appeals.
"However 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."
It is thought Hussain was responsible for the bus bombing, in which 13 people died, Khan the Edgware Road blast that killed six people; Tanweer for the Aldgate blast, which killed six, and Lindsay for the Russell Square explosion where 26 people were killed.
In other developments:
- Ten addresses in West Yorkshire and one in Aylesbury, Buckinghamshire, have been searched. Seven of the 10 West Yorkshire searches are still ongoing.
- Police have extra time to question a man, arrested on 12 July on suspicion of the commission, instigation or preparation of acts of terrorism, and held at a central London police station
- Police have taken more than 800 witness statements and received 3,500 calls to the anti-terrorist hotline
- The wreckage of the bombed number 30 bus has been moved from Tavistock Square in central London for further forensic examination
Earlier, Tony Blair said it was time to stand up to the "evil ideology" behind the London bombings and other attacks.
He said such violence was not a response to any particular policy or injustice, but was a "fanaticism" that had to be confronted.
The prime minister told Labour party members it would be a "misunderstanding of a catastrophic order" to think extremists would act differently if the developed world changed its behaviour.
"If it is the plight of the Palestinians that drives them, why, every time it looks as if Israel and Palestine are making progress, does the same ideology perpetrate an outrage that turns hope back into despair?
"If it is Afghanistan that motivates them, why blow up innocent Afghans on their way to their first-ever election?
Germaine Lindsay (above): Jamaican-born man living in Buckinghamshire. Believed to have carried out King's Cross attack.
Mohammad Sidique Khan: Aged 30, from Beeston, Leeds, recently moved to Dewsbury, married with baby. ID found at Edgware Road blast site.
Hasib Mir Hussain: Aged 18, lived Holbeck, Leeds. Reported missing on day of bombings. Said to have turned very religious two years ago. ID found in No 30 bus.
Shehzad Tanweer: Aged 22, born Bradford, lived Beeston, Leeds. Studied religion in Pakistan. Forensic evidence linking him to Aldgate blast.
"If it is Iraq that motivates them, why is the same ideology killing Iraqis by terror in defiance of an elected Iraqi government?
"What was 11 September 2001 the reprisal for?"
But some Labour left-wingers saw a link between the Iraq war and the attacks.
John McDonnell, Labour MP for Hayes and Harlington, said it was "intellectually unsustainable" to say the war in Iraq had not motivated the bombers.
"For as long as Britain remains in occupation of Iraq the terrorist recruiters will have the argument they seek to attract more susceptible young recruits. Britain must withdraw now."
Labour ex-minister Clare Short, who resigned over the Iraq war, told GMTV's Sunday programme she "had no doubt" the atrocities were linked to Iraq.
"We are implicit in the slaughter of large numbers of civilians in Iraq and supporting a Middle East policy that for the Palestinians creates this sense of double standards - that feeds anger," she said.
The families of Khan, Hussain and Lindsay have all issued statements expressing their shock and sadness at events.
"Our thoughts are with all the bereaved families and we have to live ourselves with the loss of our son in these difficult circumstances," Hussain's family said.
Khan's family said: "We are devastated our son may have been brainwashed into carrying out such an atrocity."
Tanweer's uncle said the family had been "left shattered" by news of his involvement.
British police are now searching for those who may have helped the bombers carry out the attacks.
One house being searched in Leeds is linked to Egyptian biochemist Magdi Mahmoud al-Nashar, 33, who was arrested in Cairo as part of the inquiry into the bombings. He has denied any involvement.
Egypt's interior minister said press reports linking Mr al-Nashar to al-Qaeda were "groundless" and based on a hasty conclusion.
Other properties being searched are the Holbeck home of Hussain, the Dewsbury home of Khan, and the Beeston home of Tanweer. The property searched in Aylesbury was where Lindsay lived.
The bombed bus was moved from Tavistock Square on Saturday
On Saturday police sealed off and searched a house in Tempest Road, Beeston, Leeds, not far from where Tanweer lived.
On Friday Britain's top Muslims issued a joint statement of condemnation branding the London bombings "utterly criminal, totally reprehensible, and absolutely un-Islamic".
But Britain's highest ranking Asian police officer, Tarique Ghaffur, said Muslims and their leaders must do more than condemn the bombings.
Mr Ghaffur, the Metropolitan Police Assistant Commissioner, urged members of the community to inform on potential terrorists and their supporters.
The police would have to engage better with minorities - but minorities must take the first step, he said.
Police are urging anyone with information that could help their investigation to call the confidential Anti-Terrorist Hotline on 0800 789 321.