Pakistani security sources said yesterday that al-Qaida's "number three" was behind the alleged plot to blow up several transatlantic flights leaving the UK. They also suggested Britain wanted to allow the plotters to try a dry run, without explosives, so as to gather more evidence, but was persuaded to intervene earlier by US and Pakistani authorities. British detectives are in Islamabad working with the Pakistani security services with regard to Rashid Rauf, the Briton held in connection with the alleged plot. No decision has been made as to whether he will be extradited to Britain. Abu Faraj al-Libbi, who after...