A key suspect in the London bombings has been arrested in southern Africa. British-born militant Haroon Rashid Aswat is being held in Zambia, amid claims he may have played a major role in plotting the deadly July 7 attacks. As its biggest ever manhunt continues, it is claimed the UK denied a request from the US to apprehend Aswat just one month before the suicide bombers struck, killing dozens of people.Meanwhile, nine people were arrested in Tooting in south London in connection with the failed attacks two weeks later. Three of the four suspected would-be bombers are still on the run. The fourth prime suspect was arrested and continues to be questioned by police. Police are appealing to the public for help – warning the trio could try to strike again. An alert in the capital on Thursday led to the closure of an underground station. It is just the latest in a series of scares since the terror attacks.