At least three of the four suspected homicide bombers who carried out the deadly attacks on London's transit system last week were born in England, and all four men came from Leeds in the English Midlands, according to British media.

British media also reported Wednesday that authorities were hunting a fifth man as a suspect in connection with the blasts last Thursday, which claimed at least 52 lives on three subway trains and on a bus in central London.

Scotland Yard was unable to confirm the report.

According to British media reports, three of the four are described as British nationals of Pakistani origin, all of whom lived in and around Leeds (search), which is heavily populated with lower- and lower-middle-class blue-collar workers.

News reports have identified three of the four as Shahzad Tanweer, a 22-year-old cricket-loving sports science graduate; Hasib Hussain, 19; and Mohammed Sidique Khan, the 30-year-old father of an 8-month-old baby. Press Association, citing police sources, said police had identified the fourth suspect, but no name was reported.

Click here to read in-depth profiles of three of the men.

Police have not publicly confirmed any of the identities. Investigators will now have to determine whether the men acted alone — or had help in planning the bombings.

Tanweer's uncle, Bashir Ahmed, said his nephew had gone to Pakistan earlier this year to study religion, and that the family believed he was attending "some religious function" on the day of the bombings.

"It was total shock, I mean, it's unbelievable," Ahmed told reporters.

"Our lives have been shattered. It's impossible to describe it. We have had a very pleasant time here. I don't think we can continue here."

Many Pakistanis immigrated to the area several decades ago to work in textile mills, many of which have since shut down. The area is rife with ethnic tension and was the site of notorious race riots in 2001.

In London, Prime Minister Tony Blair (search) met with British Muslim lawmakers and pledged to open dialogue to tackle a "perverted and poisonous misinterpretation" of Islam. He also said his government would begin consultations on new anti-terrorism legislation.

Addressing the House of Commons, Blair said the government also would look urgently at how to strengthen the process for excluding from the United Kingdom those who incite hatred and make it easier to deport such people.

In an interview with the BBC, British Home Secretary Charles Clarke said the Muslim community must "stand out" against any ideology that promotes violence and bombings.

"I think that is the clarion call to us, to us as politicians, as broadcasters, to faith leaders, to lawyers, to everybody, to say we have to fight for this society we have, rather than just coasting along and assuming it's all OK," he said.

"That means standing out against, in a very strong way, anybody who preaches the kind of fundamentalism, as I say, that can lead four young men to blow themselves and others up on the Tube on a Thursday morning."

Christina Corbett, a London intelligence analyst, told FOX News that if the attacks were the work of Al Qaeda (search), the terror network would most likely have sent an expert to train the cell and extracted this person before the attack was carried out.

"It's highly likely that these four men were not working alone," Corbett said. "One of these men reportedly was 19, which is way too young to be training in a [terrorist] camp in Afghanistan." (search)

Corbett said the developments in the case could help uncover other terror cells operating in the United Kingdom.

"I don't think that further attacks have been ruled out; they were certainly expected after the [bombings in London]," Corbett said. "But as the criminal investigation proceeds, it will certainly become more difficult for the terrorists to carry out their activities."

Cops Search for Explosives, Evidence

Police raided six homes in Leeds Tuesday searching for explosives and computer files. They arrested a man, identified by the British news agency Press Association as a relative of one of the suspected bombers.

Acting on six warrants, British soldiers blasted their way into an unoccupied Leeds row house. Streets were cordoned off and about 500 people were evacuated. Hours earlier, police searched five homes elsewhere in the city. Police still weren't letting the evacuees return to their homes early Wednesday.

Authorities removed a silver Honda Accord from outside of Khan's home yesterday. The property remained clad in scaffolding and white plastic sheeting today. Documents belonging to Khan were found in the debris of the Edgware Road blast.

Neighbors of Tanweer in Leeds' garbage-strewn rows of Victorian-era red brick houses were apprehensive and hostile, walking fast past reporters gathered at the cordons. One warehouse worker, who would only give his first name, Saj, said Tanweer was a "good lad" and an athlete.

"He was quiet," he said. "He was religious. He went to every mosque here. There are loads of mosques here."

Mohammed Iqbal, a town councilor who represents the City-on-Hunslet section of Leeds, told AP that all of the homes raided belong to "British citizens of Pakistani origin."

Three of the homes were in the neighborhood he represents, Iqbal said in a phone call with AP's office in Islamabad, the Pakistani capital. He said he had just met with police about the investigation.

"This is not good for Muslims," Iqbal said. "We have businesses here. There will be a backlash."

Did Bomber Blunder?

One of the suspects had been reported missing by his family at 10 p.m. Thursday, and some of his property was found on the double-decker bus in which 13 died, said Peter Clarke, head of the Metropolitan Police anti-terrorist branch.

Some witness accounts suggested the bus bomber may have blundered, blowing up the wrong target and accidentally killing himself. A witness who got off the crowded bus just before it exploded told AP he saw an agitated man in his 20s fiddling anxiously with something in his bag.

"This young guy kept diving into this bag or whatever he had in front of his feet, and it was like he was taking a couple of grapes off a bunch of grapes, both hands were in the bag," said Richard Jones, 61, of Bracknell, west of London. "He must have done that at least every minute if not every 30 seconds."

One theory suggested the attacker may have intended to leave his bomb on the subway but was unable to board because his coconspirators had already shut the system down.

Investigators also found personal documents bearing the names of two of the other men near seats on the Aldgate and Edgware lines. Police did not identify the men.

Clarke said police had strong evidence that the man believed to have carried a bomb onto the subway train that exploded between the Aldgate and Liverpool Street stations died in the blast, and they were awaiting confirmation from the coroner.

"We have now been able to establish that he was joined on his journey to London by three other men," he said.

Leeds, about 185 miles north of London, has a population of about 715,000. About 15 percent of the residents are Muslim, and many come from a tight-knit Pakistani community, mostly from Mirpur, south of Islamabad in Pakistani-controlled Kashmir. Other pockets of the community are mostly Arab.

Khalid Muneer, 28, a spokesman for the Hyde Park Mosque in Leeds, said the community was surprised by the raids and police claims that the bombers may have come from there.

"That connection would surprise us all, even shock the whole community. We still think it's too early to say," he told AP, adding that Muslims in the area were not opposed to Britain.

"I've seen no calls in this area for jihad against British or American forces. You will not get that sentiment expressed around this mosque."

Profiles of the Suspects

Closed-circuit TV video showed all four men arriving at King's Cross by 8:30 a.m. on Thursday, about 20 minutes before the blasts began, said Clarke.

U.S. intelligence agencies are checking the names of the London bombers against their databases looking for any U.S. connection, President Bush told chief executives at a private White House meeting Tuesday.

The three suspects appear to have come from a moderately affluent sect of British society. They reportedly rode in a rental car to London, toting military style backpacks. The fourth bomber remains unidentified, but is believed to be from the Luton area northwest of London.

Several officials, including Foreign Minister Jack Straw, have said the attacks bore the "hallmark" of Al Qaeda, and one of the questions investigators presumably are trying to answer is whether the four had outside help in planning the attacks.

Jeremy Shapiro, director of research at the center on the United States and Europe at the Brookings Institution, said Europeans had been involved in suicide attacks in the Middle East, but he knew of no previous such bombings in Western Europe.

Meanwhile, forensics experts have said it could take weeks to identify the bodies, many of which were blown apart and would have to be identified through dental records or DNA analysis. Investigators say 11 bodies have been identified.

The waiting seems interminable for families of the victims.

"The police just won't tell us anything," said Elzbieta Suchocka, whose 23-year-old daughter, Monika, moved from the small Polish farming town of Dabrowka Malborska to London to become an accountant.

In Poland, Suchocka took tranquilizers to deal with the uncertainty. Her daughter was believed to be aboard the bus that was torn apart at Tavistock Square. British police arrived Wednesday to retrieve Suchocka's dental records, her brother, Marcin, told the AP at the family's home.

"For me, this is extremely difficult also, but they need this evidence to identify a person," he said. "We must have hope."

For more, go to these FOX News partners: Sky News | The Times of London | The Sun

Sky News and The Associated Press contributed to this report.