Quite the rash of Unidentified Flying Object articles on the BBC News website on Wednesday! The Ministry of Defense (MoD) declassified some files on alleged UFO sightings between 1978 and 1987, they can be downloaded for free for the first month only from the National Archive in their UFO section.
What surprised me was that there was an incident in December 1980 involving USAF policemen at RAF Woodbridge, near where I grew up (less than 30 miles away). There was also a related incident known as the "British Roswell" at Rendlesham Forest (between RAF Woodbridge and RAF Bentwaters in Suffolk). We were living in Stowemarket at the time.