BBC NEWSから。
Security sources said it was likely three men whose belongings were found at the scenes are dead - there is a question mark about the fourth bomber.
Explosives were found in Leeds and Luton after a series of raids.
Police say they have CCTV images of the four arriving at King's Cross station on the day of the bombings.
They also said they had arrested a relative of one of the four suspects in Yorkshire.
Four bombs - three on the London Underground and one on a bus in Tavistock Square in the city centre - killed at least 52 people on Thursday.
自爆テロだと、監視カメラは犯罪防止には役に立たない。
