Denmark announced a temporary closure of its airspace to all civilian drones from September 29 to October 3, 2025, ahead of the European Political Community summit in Copenhagen. The decision follows multiple incursions by unidentified drones near Danish military and civilian infrastructure, prompting heightened security measures. Authorities describe the incidents as part of an emerging pattern of hybrid attacks targeting Western Europe.
Surge in drone intrusions near military sites
On September 26, 2025, Danish defense forces detected unauthorized drone flights near several sensitive locations, including Karup Air Base, the main airbase of the Royal Danish Air Force. These drones operated both within and beyond the perimeter of the base. Additional sightings were reported over Copenhagen airports and five other municipalities between September 22 and 26. The Danish government has classified these activities as serious threats to critical infrastructure, with Prime Minister Mette Frederiksen describing them as “the most significant attack Denmark has faced in recent years.”
GPS interference raises alarm in Baltic region
Compounding concerns, Germany’s air traffic control authority reported a sharp increase in GPS signal disruptions during flights. According to Deutsche Welle, 447 incidents were recorded between January and August 2025, compared with just 25 over the same period two years ago. Most disruptions occurred over the Baltic Sea and Baltic states, a pattern experts link to Russian hybrid warfare. Such interference, known as spoofing, can mislead flight crews about their position and altitude, presenting significant safety risks.
Government declares hybrid threat
Defense Minister Troels Lund Poulsen confirmed a sustained hybrid campaign involving various types of drones, underscoring that Denmark faces “systematic” threats rather than isolated incidents. He warned that “we will see more hybrid incidents” and stressed Denmark’s need to strengthen its preparedness. Justice Minister Peter Hummelgør suggested the aim of such attacks is to “spread fear and sow division” across Western Europe. Denmark’s Security and Intelligence Service chief Finn Borch confirmed rapid responses in affected areas, including deploying helicopters to intercept suspicious drones.
Broader context of hybrid provocations in Europe
This escalation is part of a larger pattern of disruptive acts in Western Europe over the past year, including underwater cable damage, pipeline sabotage in the Baltic Sea, mysterious warehouse fires, and targeted package explosions. In September 2025, Russian provocations included dispatching over twenty drones into Poland. The Danish measures resemble a preemptive effort to counter what experts see as Kremlin testing of hybrid warfare tactics. Law provisions allow the Minister of Transport to restrict airspace for public safety, with violations punishable by fines or imprisonment.
Strategic risks for Europe
The recent spike in drone activity and GPS disruptions signals a possible intensification of hybrid warfare targeting NATO members. Analysts caution that without coordinated countermeasures, such tactics could undermine European security and critical infrastructure resilience. Denmark’s decisive action sets a precedent for other states facing similar threats in the Baltic region and beyond.
Denmark’s move to ground civilian drones until October 3 reflects a broader urgency to adapt to evolving threats, particularly in a geopolitical climate marked by increased Russian hybrid activity in Europe.
