Police officials in Britain now believe that four British-born men carried out last week’s deadly bombings that left at least 52 people dead. Three of the men lived in the city of Leeds and at least three are believed to have died in the attacks. None of them are believed to have had any criminal convictions or known connections to terrorist organizations. Police said all four men are of Pakistani descent. Closed circuit television film from the day of the bombings captured the four young men together that morning all wearing identical large backpacks similar to those carried by infantry soldiers. Police first learned of the four men when the family of one of them reported their 22-year-old son, Hasib Hussain, was missing. Police said it was Hasib who blew up the double-decker bus. On Monday investigators searched five homes in Leeds and discovered an abandoned car that may have been used by the attackers. One man was arrested in West Yorkshire. The BBC reports that detectives believe that at least three of the men died carrying out the attacks.