In response to the drone sightings this week, the USAF said it had the “the right to protect” bases in England from threats. It did not comment on whether defence mechanisms were used to target the drones.

“To protect operational security, we do not discuss our specific force protection measures but retain the right to protect the installation,” it said. “We continue to monitor our airspace and are working with host nation authorities and mission partners to ensure the safety of base personnel, facilities and assets.”

An MoD spokesman said: “We take threats seriously, and maintain robust measures at defence sites. This includes counter drone security capabilities. We won’t comment further on security procedures.”

RAF Lakenheath is home to the 48th Fighter Wing, including F-35A and F-15E fighter jets. RAF Mildenhall hosts the USAF’s 100th Air Refuelling Wing, which conducts combat support operations throughout Europe and Africa. RAF Feltwell provides housing and other services for military personnel.

British soldiers were warned last year that spies could be flying reconnaissance drones over UK military bases.