Police: Did 4 London bombers die?

Suicide/Homicide Bomber's in London?

LONDON, England (CNN) -- Police say they are trying to establish if four men died in last week's deadly London bombings, in what could be the first suicide attacks in Britain.Peter Clark, head of the Anti-Terrorist Branch, also said Tuesday one man had been arrested in northern England after a series of raids in connection with the bombings that killed at least 52 people."The investigation quite early led us to have concerns about the movements and activities of four men, three of whom came from the West Yorkshire area," Clarke said."We are trying to establish their movements in the run up to last week's attacks and specifically to establish whether they all died in the explosions."