The three bombs on the London Underground in Thursday's terrorist attack exploded almost simultaneously, British police said today. They blasts happened within 50 seconds of each other, at about 8.50am. The first explosion happened at Aldgate-Liverpool Street, followed by the blasts at Edgware Road and Russell Square.
A fourth bomb, on the number 30 bus at Tavistock Square, exploded at 9.47am.
Police had previously thought that there had been 26 minutes between the first and third explosions. The revised timetable for Thursday's attacks - which killed more than 50 and injured 700 - was established after looking at technical data from London Undergound.
Scotland Yard Deputy Assistant Commissioner Brian Paddick said: "We can clarify the position that the three bombs exploded almost simultaneously.
"Clearly, there are two possibilities here. Either you have people with the explosive devices who synchronised watches or whatever, and they have simultaneously detonated their devices at the same time.
"Or it could be these devices were triggered by timing devices that were co-ordinated to go off at the same time.
"I don't think it takes us much further forward other than to say that, bearing in mind these were almost simultaneous, we think within 50 seconds of each other, maybe that lends more towards timing devices than people actually with the bombs manually detonating. But we are not ruling out either possibility."
Although police believe the terror cell responsible for England's worst peace-time atrocity are still at large, possibly still in the country, they have no specific suspects and have made no arrests. Asked about reports that one of the bombers may be among the injured still being treated in hospital, Mr Paddick said: "As far as we are concerned this is just complete speculation. Clearly any information we receive, we will make absolutely sure there is no evidential value in any of the information before we move on to the next line of inquiry."
Senior officers fear they could have the capability to strike again. In previous al-Qaeda campaigns in Europe terrorists have planned second strikes.
Police and the security services are also working very closely with their Spanish counterparts because of the similarities to last year's Madrid bombings. A team of Spanish investigators are travelling to London. A claim for the attacks has been made in the name of al-Qaeda by a group called the Abu Hafs al-Masri Brigade which also claimed responsibility for the Madrid bombings which left 191 people dead.
The group takes its name from a top al Qaida lieutenant who was killed in a US air strike in Afghanistan in 2001.
Police also said they still did not know how many bodies were in train wreckage in a tunnel between King's cross and Russell Square. British Transport Police Deputy Chief Constable Andy Trotter said it would take some time to get the bodies out but it would be done with dignity.
The British government announced today that a two-minute silence is to be held on Thursday to remember victims of the London bombings.
PA