LONDON- Police said Tuesday they have evidence that at least one bomber died in the attacks on London's transport system, and are trying to determine whether all of them died.
At least three of the suspected bombers came from West Yorkshire, scene of a series of police raids earlier in the day, said Peter Clark, head of the Metropolitan Police antiterrorist branch.
The home addresses of three of the suspects were among the residences raided by police, Clark said.
Police believe that a bomber died in the explosion between Aldgate and Liverpool Street underground stations, Clark said.
"This investigation is going at great speed," Clark added.
CCTV footage showed that all four suspects had arrived at King's Cross station by 8:30 a.m. on Thursday, about 20 minutes before the blasts on three subway trains, Clark said.
One of the suspects had been reported missing by his family at 10 a.m. on the day of the explosion, Clark said. Some of his property was found on the double-decker bus - the scene of the fourth attack - in which 13 people died, he said.
"We have very strong forensic and other evidence that it is very likely that one of the men from West Yorkshire died in the explosion at Aldgate," Clark said, adding that this must be formally confirmed by a coroner.