A US fighter jet F-18 crashed five miles northwest of RAF Lakenheath in Suffolk, officials say.
There is currently no word on the fate of the pilot.
According to Cambridgeshire police, the plane came down in farmland on the Suffolk-Cambridgeshire border.
A Cambridgeshire Police spokesman said: “We are currently at the scene of a plane crash on farmland in Redmere, Ely.
“Details are sketchy at this stage and it is not known if there are any casualties.”