ISLAMABAD (Reuters) - Pakistan denied on Wednesday that al Qaeda chief Osama bin Laden the alleged mastermind behind the Sept. 11, 2001 attacks on the United States, had been arrested in Pakistan. Pakistan's interior minister described as baseless and unfounded the report by an official of a small Pakistani political party. Officials in Washington said they had no information to back up the report. "This is absolutely unfounded and absolutely baseless," Pakistan's Interior Minister Faisal Saleh Hayat told Reuters. Other senior Pakistan officials also denied the report. A U.S. administration spokesman in Washington said: "We have no information to substantiate...