The Obama administration will issue a warning Saturday to U.S. travelers in Europe to avoid places frequented by Westerners after new intelligence suggested an attack by Al Qaeda could be imminent, a senior U.S. intelligence official told Fox News. The travel warning is expected to be announced at 4 p.m., pending Secretary Hillary Clinton’s approval, the official said. The move is expected to have significant implications for European tourism. The travel warning will advise Americans to stay away from European tourist sites, transportation hubs and other facilities because of fresh threat information, U.S. officials told the Associated Press.