Small drones have appeared in the area around three U.S. Air Force bases in the United Kingdom this week, nearly one year removed from when similar activity happened at a base on American soil.

U.S. Air Forces in Europe shared a statement with Military.com that said that “small unmanned aerial systems were spotted in the vicinity of and over RAF Lakenheath, RAF Mildenhall and RAF Feltwell.”

Col. David Herndon, a spokesperson for U.S. Air Forces in Europe, told Military.com in an email that the drones were spotted between Nov. 20 and Nov. 25.

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“The number of systems fluctuated, and they ranged in sizes and configurations,” the statement said. “To safeguard operational security, we do not discuss specific force protection measures; however, we retain the right to protect our installations.”

U.S. Air Forces in Europe added that the drones “were actively monitored, and installation leaders determined that none of the incursions impacted base residents, facilities or assets.”

CNN reported Monday that there were an estimated five to six drones that appeared to be operating in a coordinated way.

A spokesperson for Britain’s Ministry of Defence told CNN, “We take threats seriously and maintain robust measures at defence sites. This includes counter-drone security capabilities.”

RAF Lakenheath is home to the 48th Fighter Wing, RAF Feltwell houses service members and provides support for the 48th Fighter Wing, and RAF Mildenhall hosts the 100th Air Refueling Wing.

These latest drone sightings come after it was reported in The Wall Street Journal that mysterious drones swarmed the area around Langley Air Force Base, Virginia, in December 2023 for 17 days.

They also come amid heightened concerns about surveillance on American soil, such as when a Chinese spy balloon floated across North American airspace between late January and early February 2023.

Retired Gen. Victor E. Renuart Jr. — who served as the head of United States Northern Command and North American Aerospace Defense Command, or NORAD, from 2007 to 2010 — told Military.com in an interview Monday that the use of drones near American bases, whether flown by hobbyists or foreign adversaries, is cause for concern.

“I’d say, first and foremost, they’re safety concerns,” Renuart said. “You have a balance of safety and then national security, certainly as well, that the local installations and the NORAD staff all pay attention to every single day. I can tell you, they probably get 100 reports of drone activity every day, and maybe more.”

As drones become more popular and accessible, Renuart said these incidents are likely to mount.

“It’s something that we’re going to have to deal with more routinely,” Renuart said. “It goes anywhere from nuisance to real safety to real national security concerns, depending on what the source and the intrusion really looks like. But it’s certainly something that we deal with every day.”

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