(Chris Radburn | PA File | The Associated Press) This is a Jan. 8, 2015 file photo of U.S.Air Force Base, RAF Mildenhall in Suffolk Eastern England. British police said Monday dec. 18, 2017 that they are responding to a "significant" incident at a Royal Air Force base used by the U.S. Air Force. Police say it happened at RAF Mildenhall and has urged the public to stay away from the area for the time being. Police say that further details will be released shortly.