A senior Pakistani intelligence official told reporters here Tuesday night that a leader of Al Qaeda based in Afghanistan was the mastermind of the reported plot in Britain to blow up American airliners. But the official, speaking on condition of anonymity, did not identify the leader or provide other details. He said the supposed mastermind was comparable in importance to Abu Faraj al-Libbi, a Libyan said to have been a high-ranking Qaeda official, whom Pakistan arrested in May 2005 and turned over to the United States. Full Story