A number of unidentified drones have been spotted over three United States Air Force bases in England over the last six days, U.S. officials said on Tuesday. "Small unmanned aerial systems were spotted in the vicinity of and over RAF Lakenheath,

The Air Force didn’t identify who was behind the incursions, but said officials determined there was no impact on residents or critical infrastructure.

It comes after the US Air Force (USAF) previously confirmed that unmanned devices ranging in 'size and configuration' had been tracked over three RAF bases in Suffolk and Norfolk last week