Unidentified drones have been observed hovering over a military base used by NATO in the Netherlands, the Dutch defense ministry has said.
It said military personnel deployed weapons to try to take down the drones spotted near Volkel Air Base, north of Eindhoven, between 19:00 and 21:00 local time (18:00-20:00 GMT) on Friday.
The defense ministry said the devices departed and were never recovered.
The Netherlands is among a number of northern European nations to be blighted by drone sightings around military installations and airfields in recent months. Russia has denied accusations it was involved in previous incidents.
Dutch police are investigating Friday's incident. Officials said that for security reasons they would provide no further details about how the drones or what action was taken.
As well as being used by the Royal Netherlands Air Force, Volkel Air Base hosts a US Air Force squadron as part of NATO.
The incident follows reports of drone sightings at other Dutch air bases in the past few weeks, as well as facilities in neighboring Belgium, Denmark, and Germany.
The sightings have disrupted air traffic and raised security concerns.
A lack of evidence pointing to their origins has plagued investigations into the incidents since they began in September, as in many cases the drones depart after a while.
Some European officials have attributed the sightings to hybrid warfare on the part of Russia, as the nations that have been targeted are all allied to Ukraine.
But the Kremlin has denied it has anything to do with past incursions.
Defense ministers from 10 EU countries have agreed to create a drone wall in response to the sightings, while some individual nations have sought to secure anti-drone defense measures.
