Key Facts

• The Wall Street Journal reported that nine Stratotanker refueling planes were repositioned because of an Iran threat; its sources said it was unclear whether the threat was imminent or general.
• Public aircraft tracking data reviewed by CBS News showed 10 KC-135s leaving RAF Mildenhall on Monday.
• Four of the tracked KC-135s went to Spangdahlem Air Base in Germany, one to Ramstein Air Base in Germany, four to Morón Air Base in Spain, and one to Glasgow Prestwick Airport in Scotland.
• Three U.S. Osprey transport aircraft also left Mildenhall for RAF Lakenheath in England on Tuesday; it is unclear whether those moves related to the reported threat.
• A U.S. official said the military takes steps to protect its aircraft, personnel and facilities, but did not comment on the specific movements.
• The U.S. Air Force said aircraft regularly move between bases for training and operational needs, and cited security rules in declining to provide more details.
• The U.S. Air Force removed its long-range bombers from RAF Fairford more than a month earlier, after a security incident near the base.
• Two men were charged in October in connection with the Fairford incident; U.K. Prime Minister Andy Burnham said Iran was believed to have played a part, while noting the police investigation was ongoing.