The man shot dead on an Underground train in south London on Friday was not connected to attempted terror attacks on the capital, said police. The statement came as it emerged that police have been given secret new shoot-to-kill guidelines in recent weeks. The dead man was named as Jean Charles de Menezes, a 27-year old electrician from Brazil. Mr Menezes, who lived in Brixton, south London, had been working legally in Britain for three years. This is a tragedy. The Metropolitan Police accepts full responsibility for this. To the family I can only express my deep regrets, Sir Ian Blair, Metropolitan Police Commissioner, told Sky News on Sunday. The shooting happened in Stockwell on Friday morning when armed plain clothes police officers shot a man as he tried to board a train at the Underground station. He had emerged from a house under surveillance following Thursday’s attempted bomb attacks on three Tube trains and a bus. New shoot-to-kill guidelines for armed police and surveillance officers confronting suspected suicide terrorists advise them to shoot to the head and not the body in case the suspect has a bomb. Sir Ian on Sunday admitted the police had a shoot-to-kill policy to deal with suicide bombers and that it would continue. Somebody else could be shot. But everything is done to make it right,” he said. Friday morning’s shooting at Stockwell came as the hunt continued for terrorists behind bomb attacks that have killed more than 50 people. Over the weekend police questioned two men arrested in connection with the attacks. The admission by the police that the dead man was not connected to the terror attacks will stoke debate over counter-terrorism tactics and the implication that police were operating a so-called shoot-to-kill policy against suspected terrorists. On Friday night the London-based Islamic Human Rights Commission called for a public enquiry into the shooting in Stockwell. This is an extra-judicial killing by police who have been trained in shoot-to-kill, it said. The police now face inquiries into their actions that could hit morale, and the Independent Police Complaints Commission is investigating the Stockwell shooting. Sir Ian said the force was confronting what he called its greatest operational challenge ever. They faced previously unknown threats and great danger, he added as he appealed for the understanding of all communities. Sir Ian said the dead man had been challenged and refused to obey police instructions. Police raided at least three addresses in London on Friday and made two arrests. Police Issue Pictures Of Four Bomb Suspects Police released closed circuit TV pictures of the four suspects and sought public assistance as forensic work continued on what appeared to be home-made explosive devices used on Thursday. A spokesman for the Association of Chief Police Officers said on Friday night a special project group had developed operational tactics to help police respond swiftly and effectively to such threats. The guidelines were secretly developed in consultation with police forces including Israel, Russia and the US.