The US Air Force said it responded to “suspected unauthorised drone activity” over RAF Lakenheath in Suffolk on Friday evening.
No personnel, aircraft or infrastructure were affected, a spokesperson for the US Air Force said.
It comes after unconfirmed reports that sirens were sounded at the base, which residents reported hearing from a nearby village.
A Ministry of Defence spokesperson told the it was “coordinating with all relevant parties”, adding that US Air Force security personnel responded to the reports and the situation was resolved.
“We are working closely with them to establish the facts,” they added.
West Suffolk MP Nick Timothy said he had been in touch with authorities at the base, and was told “there is no threat to the public, and the incident is now resolved”.
“Given the raised threat level, I continue to encourage everyone to report anything suspicious or out of the ordinary to the authorities,” he added in a social media post.
Earlier this week, at least 12 US Air Force aircraft departed the nearby RAF Mildenhall base.
They included two Boeing Stratotanker KC-135 refuelling aircraft, with one apparently headed towards Germany and another seen landing at Prestwick Airport near Glasgow.