Pakistani security agencies have arrested a key al-Qaeda member during a raid in its southern city of Quetta. An intelligence source on condition of anonymity told Pajhwok Afghan News the detained Nasir Mustafa was wanted to the United States in several cases.The 47-year-old Musatafa is a Syrian citizen and his name is included in the American list of most wanted men, said the official. Besides the 9/11 attacks on World Trade Centre in the United States, the detainee was allegedly involved in the 2004 bomb blasts in Madrid, Spain. A member of Taliban, who wished not to be named, confirmed the arrest of Nasir Mustafa. Speaking to this correspondent over the telephone, the source said he was living in Kandahar during the reign of Taliban. Ahmad Suleman, an al-Qaeda member, told this scribe by the telephone, Mustafa was a common member of the group. He was known as Musal al-Suri among his colleagues, said Suleman.