A U.S. B-52 bomber mistakenly loaded with five nuclear warheads flew across the United States from North Dakota to Louisiana last week, a newspaper reported Wednesday.The bomber carried advanced cruise missiles as part of a Defense Department program to retire 400 of the missiles, the Military Times said, quoting three officers who spoke on condition of anonymity. The officers said the nuclear warheads should have been removed before the August 30 flight from Minot Air Force Base in North Dakota to Barksdale Air Force Base in Louisiana, the newspaper said Wednesday.An Air Force spokesman, Lieutenant Colonel Ed Thomas, told the Military Times that the weapons were in Air Force control at all times and the missiles were safely transferred. Air Force policy does not permit officials to say whether nuclear warheads were involved, Thomas said. However, he said all nuclear weapons at Minot were accounted for.“Air Force standards are very exacting when it comes to munitions handling,” Thomas said. “The weapons were always in our custody and there was never a danger to the American public.”He said an investigation was launched and the crews involved in loading the missiles were decertified pending corrective action or training.