Drones still being spotted over UK bases: US air force

The drones have also been seen over RAF Fairford, in western England, the spokesperson said, adding to the sightings reported on Tuesday over three bases in eastern England, RAF Lakenheath, RAF Mildenhall, and RAF Feltwell.

The drones have to date not affected the bases, which are leased by the USAF from the United Kingdom.

"Our units continue to monitor the airspace and are working with host-nation authorities and mission partners to ensure the safety of base personnel, facilities and assets," the spokesperson said.

"We  do not discuss specific force protection measures, however we retain the right to protect our installations."

The UK said it was providing support to the US Air Force response, with local media reporting 60 military personnel had been deployed to help investigate the issue.