The tube carriage in which seven people died in the London bombing at Edgware Road has been removed. In a delicate operation, it was lifted by crane and lowered onto a flatbed lorry before being taken to a police compound for further forensic examination.The blast was one of four explosions on the city’s public transport system that left 56 people dead. Among those killed were the four bombers behind the July 7 attacks that police say bore all the hallmarks of al Qaeda. Three were Britons of Pakistani descent. All three visited the country last year. Authorities there are making efforts to track down militants. Some 25 people were detained in raids in Pakistan linked to investigations into the London attacks. It is reported that one of them is a major al Qaeda figure suspected of close links to the bombers.