SIMON ISRAEL: On the streets of London, police presence is total. This huge investigation is far from over. The fact four British suicide bombers may be dead does not diminish its urgency. There is no doubt they had support, the plotters and planners as described by senior security sources.
But Channel 4 News now understands there's a fifth man. He was captured on CCTV at Luton with the four before they set off for the capital. More details are emerging from yesterday's raids in Leeds of the bombers' path to what they saw as martyrdom and the rest of the world saw as wanton carnage in London last Thursday.
We now know at least three traveled down from Leeds to Luton, two coming from the city's Beeston area and another from nearby Dewsbury. It is believed three traveled down in hired cars and rendezvoused with a fourth and perhaps a fifth in Luton and was seen boarding the 7:48 'Thameslink' train to London, arriving at King's Cross at 8:20, and from there were spotted on the station's main concourse before entering the underground.
M. J. GOHEL: There can be little doubt that these four individuals could not have acted upon their own. They must have had somebody who did the recruiting, who did indoctrinating, or perhaps provided finance, the organization, planning, the technical know-how.
And therefore we must look at the possibility -- the grim possibility that there are other members of the cell still out there and they could perpetrate another follow-on attack.
SIMON ISRAEL: Having answered the question of who the bombers are, the intelligence services are now trying to find out where they've been and who they've met. A senior security source has told Channel 4 News that one of the bombers is connected by a mobile phone number to someone already facing terror charges in the UK.
As more lay wreaths at the scene of the bus bomb, it's also reported that Britain has asked Pakistan for information on the young man believed to have visited that country in the months before blowing himself up on the Number 30.
JIM LEHRER: Our second report is from Leeds, where some of the alleged bombers lived. John Sparks of Independent Television News reports from there.
JOHN SPARKS: Poles and sheeting erected with speed. Local residents take note but carry on with the daily routine. The suburbs of Leeds now host what intelligence officials call the nightmare scenario: Disaffected young men hidden by normalcy yet twisted with rage.
Eighteen-year-old Hasib Hussain lived here at Number 7 Colenso Mount. He carried his bomb filled rucksack on to the Number 30 bus. Tall, softly spoken and unemployed, his father sent him to Pakistan after some poor behavior. He would later become a devout Muslim.
Mohammed Tanweer loved his son. He just bought him a brand-new red Mercedes. Twenty-two years old, Shahzad Tanweer loved cricket and studied at a local university. Last year, he went to Pakistan to study the Koran but last night his friends told us he was just the same when he returned.
PARVAZE KHAN: I seen him on Monday, last Monday, and he drove past on his way back.
JOHN SPARKS: But Shahzad Tanweer carried the bomb on to the Aldgate east tube, the first bomb to explode. His uncle, who runs the local kebab shop, couldn't believe it.
BASHIR AHMED: I seen him growing up. He was a decent child, and he was a very gentle person. Personally, I cannot believe that he could be involved in a situation like this.
JOHN SPARKS: I asked about Mr. Tanweer's family.
BASHIR AHMED: I think we are broken.
JOHN SPARKS: Broken?
BASHIR AHMED: Broken.
JOHN SPARKS: Thank you very much.
JOHN SPARKS: The Tanweer family, devastated by loss, and also aware of how they may be judged by society. They said they didn't think they could survive here much longer.
Dewsbury, on the outskirts of Leeds -- more scaffolding, more police and another tale of the seemingly unremarkable. Thirty-year-old Mohammed Sadique Khan lived here, an émigré from Pakistan, he recently married, having met his life at a local university. He's thought to be responsible for the Edgware Road bomb.
We've been told the fourth bomber, who detonated a device on the Piccadilly line, came from this area. We've been told, however, that he moved to Luton last year where he was living with his girlfriend. That may have been the reason for the Luton early last Thursday morning.
A general impression of the man is now emerging from the suburbs. But the local community, the media and the families themselves are still a long way from knowing them, what turned them into extremists and when and how it happened.