WASHINGTON, D.C. (WOWO) Drones are emerging as a growing security threat near military installations, prompting concern from Europe to the United States.

Belgium has recorded 14 unidentified drone sightings over just two months, with the latest over Kleine-Brogel Air Base. The NATO-linked facility houses Belgium’s F-16 fighter fleet and U.S. tactical nuclear weapons and is preparing to host F-35A jets.

Belgium’s Defense Minister Theo Francken said authorities tried using a drone jammer and pursued the drone with a helicopter and police vehicles, but lost it after several kilometers. He suggested the flights could have been part of a spying operation.

“The drone jammer was used, but without success,” Francken said.

The issue is not confined to Europe. U.S. military bases have reported similar incursions, including Camp Pendleton in Southern California, Langley Air Force Base in Virginia, and repeated sightings in New Jersey. Officials warn these incidents expose the limits of current counter-drone defenses and raise serious concerns about espionage and surveillance.

Military and security experts say protecting sensitive sites against small, agile drones is increasingly difficult, and incidents like these are likely to continue.