Up to four would-be suicide bombers were feared to be on the run Thursday night after an attempt to reproduce the carnage of 7/7 on London's transport network ended in failure. Bombs that had been carried onto three tube trains and a bus at different points across the capital did not explode, apparently because their detonators, which caused small blasts when they were activated, failed to blow up the rest of the devices.
At least one of the bombs was being carried on a tube train in a rucksack by a man who shouted in surprise when it failed fully to explode, and who appears to have then vanished in the scenes of panic and confusion that followed. A second was carried onto a tube by a man who dodged fellow passengers and fled when its detonator apparently went off.
Police and anti-terrorist officials were clearly delighted at the "forensic bonanza" that they say the bombers' failure offers, and each of the devices will be examined for clues to the identity of the bomb makers. But the failure to capture any of the men at the scene means that a group of dedicated would-be bombers remains at large.
Sir Ian Blair, the metropolitan police commissioner, said there had been a number of limited explosions but that a number of the devices remained substantially unexploded -- and that the clear intention of the bombers had been to kill.
It is believed police have recovered four viable bombs, one from each of the four scenes. Three of these were of a similar size and one was smaller. One is believed to have contained nails. They were all in rucksacks, and it is understood they bore similarities to those used by the four suicide bombers in the city on July 7.
If the detonators did explode, it is unclear whether they were not properly connected to the main body of the device or whether the bulk of the explosive was faulty or degraded.
Two people were seen running away from the Shepherd's Bush and Warren Street tube stations, but it is thought packages were possibly left at the other two sites, on the tube at Oval and on the back seat of the upper deck of a bus in Shoreditch. Police are looking for four bombers, as they think it is unlikely that fewer than four people could have been involved given the almost simultaneous nature of the incidents. Police were Thursday night combing through every frame of CCTV tapes recovered from the scene to see if they could spot suspects.
The bombers followed a pattern almost identical to the attacks of 7/7, with three tube trains or stations and one bus being subjected to nearly simultaneous assaults -- one in the east of the capital, one to the south, another to the west and one near the northern edges of the city center.
After the July 7 attacks, a group calling itself the Secret Organization of the al-Qaida Jihad in Europe posted a claim of responsibility on an Islamist Web site, declaring: "The heroic mujahideen carried out a blessed attack in London, and now Britain is burning with fear and terror, from north to south, east to west."
The attempted bombings brought chaos briefly to London and triggered panic on parts of its transport network. They may also signal that the capital is the target of a sustained terror campaign, counterterrorist officials say.
Detectives and security officials are attempting to discover whether the bombers are part of the same group that murdered 52 people 14 days earlier or whether they are "copycat" attackers inspired by the slaughter. Anti-terrorist officials Thursday night said the former was more likely. "They had the same pattern and the same objective," one anti-terrorism official said.
Witnesses said a fine white dust had been scattered by some of the small explosions, but Scotland Yard said there was no evidence that any chemical or biological agents had been used. The London Ambulance Service said it had not taken any injured to hospital, although there were unconfirmed reports that one person had walked into a hospital for treatment.
Sir Ian said: "Clearly, the intent must have been to kill. You don't do this with any other intention. The important point is that the intention of the terrorists has not been fulfilled." He said it was too early to say whether the blasts were connected with al-Qaida.
"Obviously this is a very worrying development, as in one way it appears to be a repetition of the events two weeks ago. On the other hand it's a very positive breakthrough in that the recovered materials give us forensic opportunities."
Tony Blair urged Londoners to remain calm and said he hoped the city would quickly get back to business. "We can't minimize incidents such as these, because they obviously have been serious in the four different places," the prime minister said. "I think all I'd like to say is this, that we know why these things are done -- they're done to scare people and to frighten them, to make them anxious and worried."
Sir Ian also sought to ease fears and said it was "time to get London moving" again.
In the city, attacks triggered an instant wave of selling. But it was not close to the scale of July 7, when the FTSE 100 plunged more than 200 points, and the blue-chip index quickly recovered to end the day 6.4 points higher at 5,221.6. Analysts said share prices had bounced back as it became clear the attacks had not caused the same devastation as two weeks ago. The sterling held firm against the dollar and the euro. But the fact that London has now been attacked eight times in 14 days is certain to damage confidence in the security of the transport network and may hit the tourism industry.
Emergency services received their first call at 12:38 p.m. from people alerting them to a blast on the Northern line at Oval station, in south London. Witnesses said they had heard a sound "like the popping of champagne corks" from a large black rucksack on a train seat, and the carriage had begun to fill with smoke. When the train pulled into the station a young man next to the bag dashed out of the train and fled into the street.
The next call came from the northernmost explosion, at Warren Street underground station, where witnesses described a small blast that blew apart a rucksack being held by a passenger who was said to have shouted out in surprise. Panic followed as the carriage filled with smoke and people attempted to escape.
"There was no way to get out, but everyone was trying to," said Sofiane Mohellebi, 35, a French man living in London. "People were trying to pull others down to get out of the way. You don't know what it's like until you are inside. There was screaming and panic."
There was no panic when Shepherd's Bush underground station in west London was evacuated at around the same time, apparently after a device that had failed to explode was spotted on the Hammersmith & City line.
In the east of the city, the attack came on a No. 26 bus in Hackney Road, Bethnal Green. Its driver, Mark Maybanks, reported hearing a bang at the rear of the top deck, and ordered his passengers off when he found a black bag abandoned under a seat. Maybanks, 38, said: "I've never been so frightened in my life as when I went up the stairs. After what happened earlier this month I didn't know what I would find."
Amid fears of a possible backlash against Muslims in Britain, Sir Ian warned: "No community should be smeared with responsibility for these matters. These are criminal acts and we are in pursuit of a set of criminals." Two arrests made during the day, including the seizure of a man with a rucksack near Downing Street, were later said to be not connected with the attacks.