British police hunting the London bombers have made a ”series of arrests” following the identification of one of the attackers who died in the blast on a London bus last Thursday.
The arrests were made during raids and searches of six properties in the northern city of Leeds, about 320km from London, early on Tuesday.
Police said investigations ”accelerated” after a suspect believed to have blown up the London bus was identified as being among the victims.
It is not yet clear whether the man was a suicide bomber who died deliberately or whether he had ”problems with the device”, security sources said.
Thursday’s explosions on three subway trains and a bus killed at least 52 people and left hundreds wounded.
Four bombers were among those killed in the attacks, Sky News reported, quoting police sources.
Detectives believe that all four were British citizens, Sky News said.
Police earlier on Tuesday made ”highly significant” raids and searches at several homes in Leeds in connection with the devastating bomb blasts.
Anti-terrorist officers assisted by army bomb-disposal experts carried out a controlled explosion at a housing complex in Leeds, in a search for suspicious material and explosives.
A police robot was used in the bomb-disposal operation, which also prompted the evacuation of up to 600 people from homes, an old-age home and a mosque.
Ian Blair, the London police chief in charge of the raids, spoke of a ”highly significant” and intelligence-led operation that was directly linked to the London bombings.
Altogether six homes were affected by the raids. Police initially said no arrests had been made but added that details of the outcome would be given later.
In a separate move, police on Tuesday closed the main railway station in Luton, north of London, to remove a vehicle from a car park that may have been linked to the attacks.
Police said Tuesday’s actions followed about 1 700 calls from the public with information. Officers had also begun to sift through 2 500 hours of closed-circuit television film recording the events of last Thursday.
The Times newspaper, citing the French paper Liberation, reported on Tuesday that high-grade military explosives are believed to have been used in the attacks on three underground trains and a bus.
”The nature of the explosives appears to be military, which is very worrying,” French anti-terrorist police chief Christophe Chaboud was quoted as saying.
Police on Tuesday named two more victims of the blasts, 30-year-old Philip Russell and 28-year-old Jamie Gordon, following a lengthy process of identification. Earlier, Susan Levy, a 53-year-old mother of two, had been officially named as the first victim.
Meanwhile, the United States Air Force on Tuesday rescinded a ban on military personnel entering London in the immediate aftermath of the attacks.
Following outspoken criticism of the ban from British police, transport and tourism chiefs, the ban affecting about 10 000 servicemen stationed at bases in Britain was lifted.
Scotland Yard chief Ian Blair said he was ”disappointed” by the US move, and Bob Kiley, London’s transport commissioner and himself an American, called it ”not smart”.
However, a spokesperson for the US Air Force in Europe insisted that the decision was made to avoid hindering the rescue operation in London last week.
”We wanted to keep unnecessary people away from those areas so as not to disrupt the mass transit system,” she said.
Buckingham Palace revealed on Tuesday that Queen Elizabeth II has donated a ”substantial sum” to a victim relief fund set up for relatives of those who died.
”The queen recognises that the aftermath of the bombings will lead to financial hardships,” a spokesperson said. — Sapa-DPA, AFP