The family of Britain's first suicide bomber today said they could not comprehend why he had become a mass murderer.
Shehzad Tanweer, 22, was an outwardly ordinary young British man, a university graduate who studied sports science and loved cricket and football.
His father owns a fish and chip shop in Beeston, Leeds where he had lived all his life.
On July 7 he was the first of a four-strong suicide team to die when his bomb exploded on a London Underground train near Aldgate station.
Seconds later his friend Mohammed Sadique Khan, 30, who was from Dewsbury, West Yorkshire, blew himself up on a train near Edgware Road and another friend died in a blast on a train near King's Cross.
The fourth bomber, 18-year-old Hasib Hussain, from the Leeds suburb of Holbeck, killed himself in an explosion on the number 30 bus at Tavistock Square.
Tanweer, Khan and Hussain were all British with Pakistani ancestry.
Tanweer's uncle Bashir Ahmed, 65, said the bomber's family were destroyed.
Speaking at the family home Mr Ahmed said: "There is no explanation I can come to. "Our lives have been shattered. It's impossible to describe it.
"He was proud to be British. He had everything to live for. His parents were loving and supportive. They had no financial worries.
"He was intelligent. He went to university. His plan was to go into sports.
"The family is shattered. This is a terrible thing. It wasn't him. It must have been forces behind him."
Mr Ahmed said his nephew went to Pakistan for two months earlier this year to study religion.
But he denied that his nephew travelled to Afghanistan and took part in training camps.
"There is no way, I have seen his passport," he said.
Police and the security services fear the bombers could have been acting on the orders of an al Qaida mastermind and there may be another bomb team waiting to strike.
Asked whether he believed they were part of a larger cell Home Secretary Charles Clarke said: "A central hypothesis which has to be tested and investigated is that the individuals we know about were working within a wider community."
Mr Clarke, meeting European union interior ministers in Brussels today, also revealed that police were examining telephone records in the hunt for the bombers' accomplices.
He said: "We are looking very, very closely at the relationship between the people who may have committed the offences and the wider network around them.
"The telecommunications data is an important weapon in investigating that."
Mr Clarke is today seeking Europe-wide agreement on the retention of huge amounts of personal mobile phone and email records which would help future anti-terrorist investigations.
Prime Minister Tony Blair was "shocked" to learn the bombers were born and raised in the UK, his official spokesman said.
"But he is determined that we should take on this extremism," the spokesman added.
"It is his view that this is not a problem that is limited to this country, but it is a symptom of a much bigger problem and we need to look at that.
"This problem didn't start in this society, in this country. It started beyond our shores."
The bombers appear to be the security services' worst nightmare, so-called "clean skins", apparently ordinary young men who were below the intelligence radar.
Detectives are working furiously piecing together their lives as neighbours in West Yorkshire told of their shock that suicide attackers had been living in their midst.
Like Tanweer, Khan seemed an unlikely suicide bomber. Friends said he was married with an eight-month-old baby girl and that he worked with disabled children in a primary school.
Hussain lived with his parents and neighbours said he had become "very religious" two years ago.
When he left his home last Thursday morning, with only a few hours to live, he had told his parents he was going to London for the day with friends.
At 10.20pm they reported him missing to the police casualty bureau, providing one of the vital clues which led detectives to Leeds.
In a series of raids in West Yorkshire yesterday, including on the suspects' homes, detectives found an apparent bomb factory and explosives were also found in a car at Luton station.
At least three of the bombers are thought to have used hire cars to travel from West Yorkshire to Luton last Thursday morning.
All four men then boarded a Thameslink rail service to King's Cross where they were captured on CCTV just before 8.30am carrying large military-style rucksacks. They then set out to deliver their bombs.
A senior security source, who has viewed the CCTV footage, said: "They were chatting. You would think they were going on a hiking holiday."
Detectives believe the suspects probably lacked the expertise to plan the operation or construct the bombs themselves and were more likely to have been recruited by a more senior figure.
One senior security source said: "Where is the person who had the expertise to organise it all? There is the possibility that it could be al Qaida - someone who would have been sent to the country to do the preparation and then would have left the day before the attack. Is the capability to mount an attack still somewhere else?"
Terrorism lecturer Professor Paul Wilkinson said he believed the men were expendable pawns in an international al Qaida operation.
He said: "I just don't believe this would have been four young men acting on their own.
"There would have been another person who primed and guided them and lured them into extremism."
At least 52 people, including the bombers, died in last week's attacks.
Inquests into the deaths of seven victims opened today.
A total of 51 injured victims remained in hospital today, health officials said