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.

LONDON—The U.K. military deployed around 60 personnel to help protect U.S. military bases in East England after a spate of mystery drone sightings.The U.K. forces are working with the U.S. Air Force as it seeks to understand why drones have been lingering over the bases during the past week,