Quotes of the Day

They looked pathetic without backpacks filled with explosives. Naked except for their underwear, vomiting and spitting to clear out the tear gas police fired into their west London hideout, two forlorn men wanted for attempting to bomb London's transport system on July 21 surrendered to police after a three-hour siege. "Mohammed, Mohammed, come out, we won't hurt you!" the police kept shouting. But when no one came out, officers fixed a strip of plastic explosive and blew off the front door of the fourth-floor apartment where the men had taken refuge. The tear gas was next. Unlike the Madrid train bombers — who blew themselves up in April of last year rather than be captured — Ibrahim Muktar Said, suspected of trying to bomb a No. 26 bus, and Ramzi Mohammed, thought to have tried to bomb a train at Oval station, showed no inclination for suicide. "I've got rights!" one of them shouted to police, before finally giving himself up.

Just a few hours later in Rome, Italian police caught Hussain Osman, alleged to have tried to blow up a train at Shepherd's Bush, among the umbrella pines and oleander of the Tor Pignattara neighborhood on the city's southeastern rim. According to an Italian Interior Ministry official, British authorities provided their Italian counterparts with the number of a cell phone registered to Osman's brother-in-law, which they believed Osman was using as he tried to evade the massive British manhunt.

"In the course of two days, he went from London to Paris to Milan and finally Rome," the official says. Once there, he holed up in his brother's apartment, which police surrounded with 60 special agents. After they burst in, he quickly surrendered.

The fourth suspected bomber was already in custody. He had been grabbed at 4:30 a.m. last Wednesday on a quiet, leafy street 4 km outside Birmingham city center. Police swarmed down the slim garden path of a nondescript brick house and surrounded the back door, leading into a tiny bedsit apartment. "Hassan! Hassan!" they shouted. Neighbors saw blue and yellow flashes and heard explosions. Inside, antiterror officers found their bleary-eyed quarry, Yasin Hassan Omar, suspected of trying to bomb an underground train at Warren Street station, who scuffled with them and was immobilized with a 50,000-volt blast from a Taser gun.

And so, in just eight days, the biggest manhunt in the history of British policing nabbed the four known members of the gang suspected of trying to bomb the transport network on July 21. More than 6,000 police, half of them armed, put on an unprecedented show of force in London last week, watching every underground station and patrolling trains, buses and streets. "We're here to offer reassurance, madam," one polite bobby in a flak jacket told an inquisitive pedestrian. But even the best police work can't lift the cloud of fear and unease hanging over the city. No one had anticipated the attacks of July 7 or July 21, and the bombers and suspects were not on any terrorist-watch list. Are there other gangs ready to commit mass murder as they offer up their own lives to their dark vision of Islam? Though the most wanted men in Britain have been caught, the investigation still has a lot of unsettling loose ends.

British and U.S. officials have told Time that police have not yet found any forensic link between the July 7 and July 21 suspects: no phone calls, documents or other evidence tying the two groups together. Moreover, contrary to earlier speculation, the bombs used in the attacks came from different mixtures of home-made explosive, according to a British official. That means either that the same "chemist" made two different batches, or that more than one chemist was at work, and may still be on the loose.

There are also signs of a wider network of accomplices: a fifth bomb, found abandoned after the July 21 attacks in a park in west London (the man police suspect was supposed to use it — Wahbi Mohammed, the brother of Ramzi Mohammed — was also arrested last week), and the 16 bomb components found in the trunk of the car left at Luton train station by the July 7 suicide bombers. "Was there supposed to be a fifth bomber on July 7, too?" asks a British official. According to Italian authorities, Osman, who was born in Ethiopia, was able to use a dense network of contacts from East Africa for shelter as he made his way to Rome. They worry that Italy could be the next jihadist battleground.

Investigators are skeptical that the second London attack could have been put together by a copycat cell in only two weeks. On the other hand, they note that the July 21 operation did appear to be less prepared, especially because the explosives fizzled. "Al-Qaeda doesn't let amateurs out," says Dominic Armstrong, head of research and intelligence at the London-based private security firm Aegis Defence Services. A U.S. counterterror official told Time that the British and U.S. governments are open to the idea that the two attacks "may have been planned independently of each other."

Not only is there no clear link between the two sets of suspects, there is no established link between either group and al-Qaeda or any other known terror network, say British officials. There are lots of tantalizing links back to Pakistan from the July 7 gang, three of whom had parents born there. When Shehzad Tanweer — who killed seven on a train near Aldgate station — and Mohammed Sidique Khan — who killed six at Edgware Road station — left Leeds to visit Pakistan in 2004, they were frequently seen with members and recruiters of the banned militant organizations Lashkar-e-Toiba and Jaish-e-Muhammad, according to several people in Samundri, a town near the village where Tanweer stayed with his uncle.

A Lashkar-e-Toiba member in a nearby village told Time, "I was introduced to Tanweer last year, too. He had come to visit a madrasah." The militants who took Tanweer around treated him as someone worthy of respect, according to the villagers, even though he was only 21. Locals also remember him discussing atrocities against Muslims and distributing material favoring jihad. These links strongly suggest that Tanweer and Khan could have hooked up with al-Qaeda. The nature of the July 7 bombings also has many hallmarks of the worldwide terrorist group: meticulous planning, spectacular co-ordinated attacks and a goal of causing maximum civilian casualties and social disruption. Nevertheless, no hard evidence linking the attacks with al-Qaeda has been unearthed.

Significant foreign ties for the July 21 suspects are much less evident. The man arrested in Birmingham, Omar, 24, came to Britain from Somalia when he was 11, and Said, arrested in west London, came from Eritrea when he was 14. Radical Islam does have strong roots in east Africa, where al-Qaeda has bombed the U.S. embassies in Kenya and Tanzania and a Kenyan hotel, and almost shot down an Israeli airliner full of tourists. Matt Bryden, Horn of Africa project director with the International Crisis Group in Nairobi, has co-authored a report that concludes a "new, ruthless, independent jihadi network with links to al-Qaeda" has arisen in Somalia, and fears that "jihadis will gradually find growing purchase among Somalia's despairing and disaffected citizenry." Nevertheless, British officials say there is no discernible operational link to the region for the July 21 plot, and believe the men may have "got jihad" in London.

According to Italian news reports, Osman has insisted to Italian authorities that any July 21 team had nothing to do with the one on July 7. He reportedly met Said at a gym and began discussing politics in a small group without any contact with al-Qaeda, except what they read on the Internet. He is reported to have said he watched videos supposedly showing U.S. atrocities in Iraq, and wanted to protest. British officials don't know if this is true, but are taking seriously the possibility of a self-starting cell. Shane Brighton, of the Royal United Services Institute in London, says "self-radicalization" is a growing concern. "If you already accept that there's a historic struggle between Muslims and the West and that the only resort is violence," he says, "you don't need to sit at the feet of an imam for months. You just need to watch the news to have your mind-set reconfirmed." Those who have self-radicalized can then turn to "Google terror": using the Internet for bomb recipes, how-to videos and moral support — and thus slip beneath the radar of the security services. The July 21 suspects apparently found disaffection aplenty in Britain. Omar, who came to Britain as a dependent of his elder sister in 1992, had led a feral life in Mogadishu and was not prepared to cope well in the big city. Jamal Mohammed, who played football with Omar in London, told the Independent newspaper that Omar had said he used to hang out with militiamen in Mogadishu and was fascinated by their guns. "He said he had lived on the streets during the day, getting what food he could," said Mohammed. In London, Omar moved through a series of foster homes and attended Aylward secondary school in north London, which has a truancy rate three times the national average. A schoolmate said "he was quiet and picked upon and didn't have friends." By 18 he was declared a "vulnerable young adult" and put into a one-bedroom apartment on the ninth floor of a grim housing project called Curtis House in Enfield, north London.

The building has become home to a transient population of Afro-Caribbeans, Chinese, Poles, Somalis, Turks and homegrown Brits. The elevators stink of urine and used needles litter the stairways. Omar lived off state benefits worth at least $150 a week. "I never once saw him working," says Mohammed Hassan, owner of the nearby Billy's Food Shop. "He and his friend used to sit on the wall in the car park just down the road smoking cannabis." Omar once got angry at Hassan for selling liquor in his store. "He said I was a bad Muslim. I told him, 'Better than stealing.' When I worked at the shop across the road, he was caught stealing a can of tuna. I didn't like him."

At a Turkish grocery a few blocks from Curtis House, the owner's wife, Nursal, remembers once talking to Omar about a terrorist attack by al-Qaeda, saying it was terrible. "He said, 'Why? Those people [the victims] are killing Muslims.'" His classmate recalls that "he got religion three or four years ago and grew a beard. He changed. I think he was lonely."

But he did get a roommate: Said, who arrived from Eritrea in 1992 and moved in with Omar a couple of years ago. Known as a bully at school, he served time in five juvenile jails after being convicted in 1996 for gang robberies at knifepoint. One of the jails, Feltham Young Offender Institution, was where shoe bomber Richard Reid had earlier turned to Islam. Following the Sept. 11 attacks, several Muslim prison clerics were suspended after being accused of inflammatory preaching; one had worked at Feltham, where prison officers found pamphlets describing the U.S. as "the great evil which must be wiped out."

At Curtis House, Omar and Said played football on Sundays with some East Africans, but mostly kept to themselves. Some neighbors say they held prayer meetings. Last month, Samantha Jones, whose son Conor, 11, used to play football with them, saw them take "40 or 50 cartons up in the lift. They said it was wallpaper stripper." Police now believe their apartment was the bomb factory for the July 21 attacks. Nicola Hannay-Young, 15, who lives on the second floor, said Omar and Said and sometimes their friends "were in and out six or seven times a day. One had a dark blue plastic carrier bag that he carried very tightly." Traces of explosives were reportedly found in the building's garbage chute, and explosives were removed from Omar's apartment and a nearby garage.

The police were delighted with the rapid progress in locating the July 21 suspects, but the next steps may be harder. Investigators this week will presumably try to play each suspect against the other, hoping to elicit information that will fill in the many gaps about how the attacks were planned and co-ordinated. Antiterror investigators will also turn their attention to "the support networks," says a British police source. Until they are wrapped up, says antiterror police chief Peter Clarke, "the threat remains, and is very real."

And that is what is really worrying other British officials. Of the July 7 and July 21 suspects, only one had previously even tweaked the interest of the security services, implying that many more homegrown terrorists networks could be out there: Eritrean, Jamaican, North African (responsible for the Madrid bombings), Pakistani, Somali and perhaps many others in a country with 1.6 million Muslims, 4% of whom, according to an ICM poll published last week, believe "it is acceptable for religious or political groups to use violence for political ends." One official estimates there are now at least 800 Muslims with jihadist leanings in Britain who ought to be under surveillance or deported, half of whom are British citizens and cannot be made to leave.

The security services are likely to need more resources to combat that threat, even though their budget has increased 20% in the past year. At a press conference last week, Prime Minister Tony Blair backed tougher measures to fight terrorism, including using intercept evidence in court and longer periods of detention without charge — the police want up to 90 days instead of the current 14. Even with some Britons questioning the police's unprecedented tactics (see box), Blair seems likely to get most of what he wants.

In Pakistan, President Pervez Musharraf attacked the same problem in a different way. He announced that he would ban all foreigners from studying in the country's more than 10,000 madrasahs, some of which preach jihad or have al-Qaeda links. Such measures might have made it harder for the July 7 bombers to link up with the radicals they found in Pakistan. Musharraf said 1,400 foreigners would be immediately affected. "We will not allow madrasahs to be misused for extremism," he declared. But he announced similar measures in 2002 and did almost nothing. Musharraf is unrepentant. "We have to proceed in a manner that will succeed, and success is not so black and white," he said.

In that sense, Pakistan's problem and Britain's are different not in kind, only in degree. In Birmingham, just a few meters from where Omar, the suspected Warren St. bomber, was arrested, Tom Wheeldon is apprehensive and uncertain. "The neighborhood feels different now. I don't know who's who," says Wheeldon, an 86-year-old World War II vet. "I knew who the enemy was [during the war]. But now the enemy is within; you can't see them." To prevent future attacks, the police and the public will need a much clearer idea of who the enemy is.

• J.F.O. McALLISTER / London
• After a swift and sweeping manhunt, police have the four suspected London bombers in custody. Now investigators begin to unravel the terrorist plot