The discovery follows the arrest of multiple men under the UK Explosives Act. RAF Fairford, the only site in Europe where the US Air Force maintains heavy bombers and currently hosts five B-1 Lancers, is operating under FPCON Delta, the highest alert level. Security also increased at RAF Lakenheath and RAF Mildenhall, with Lakenheath on FPCON Charlie. While Iran's Revolutionary Guard has previously targeted Fairford, British authorities have not yet confirmed a motive for the arrests.
