Denmark is grappling with a series of disruptive drone incursions that forced multiple airports, including Aalborg, to close temporarily, raising concerns over the security of critical infrastructure across Europe.
The incidents mark the second such series in just days, prompting European ministers to schedule urgent talks on Friday about establishing a “drone wall” to defend against aerial threats.
The Danish authorities reported that the drone sightings began shortly before 10pm on Wednesday and continued until just before 1am on Thursday.
Aalborg airport, which also hosts military operations, halted flights for several hours. Billund, Denmark’s second-largest airport, also closed its airspace temporarily, while other airports in Esbjerg, Sønderborg, and Skrydstrup—home to Danish fighter jets—were similarly affected. Earlier, Copenhagen airport had shut down Monday night after three drones were detected.
European Commission President Ursula von der Leyen, who has long advocated for advanced drone defense systems, emphasized that the Friday meeting would focus on the detection and neutralization of incoming drones.
“One thing that we will have to do is detect these incoming drones. This is not super-easy to do. We’re not talking about big fighter jets and planes coming in. No, we are talking about the latest technology developments,” said Thomas Regnier, the Commission’s spokesperson on defense.
The meeting will include ministers from Denmark, the Baltic states, Finland, Poland, Romania, and Bulgaria. Discussions are expected to explore EU funding options, including support from the €150bn (£131bn) Security Action for Europe loans scheme. The aim is to develop a coordinated approach to counter drone threats and secure vital infrastructure.
Denmark’s Defense Minister, Troels Lund Poulsen, described the incidents as a “hybrid attack” likely conducted by a professional actor, noting the systematic operation across multiple locations simultaneously. “This is an arms race against time because technology is constantly evolving,” he said, highlighting the sophisticated nature of modern drone threats.
Prime Minister Mette Frederiksen stressed the seriousness of the situation, noting she had spoken to NATO Secretary General Mark Rutte about the ongoing risks to Danish airports.
Among the theories under investigation is that the drones may have been launched from the sea, with online trackers showing the presence of two Russian ships in the vicinity at the time. The Russian embassy in Copenhagen dismissed any involvement as “absurd” and characterized the events as a “staged provocation” to escalate tensions.
Danish police and security services are investigating numerous drone sightings, including reports over oilfields and in Stockholm, Sweden. Poulsen mentioned that Denmark is considering invoking NATO’s Article 4—a consultation clause that allows allies to discuss threats to security—for the first time in its history.
While a formal decision has yet to be made, NATO officials, including Rutte, confirmed that allied forces are working closely with Denmark to ensure the safety of critical infrastructure.
Military and drone experts explained that the drones could have been launched locally or flown long distances using advanced technologies like ground-hugging flight paths and 5G communications, which make detection challenging.
Andreas Kold Siggaard, director of Danish military drone manufacturer Hecto Drone, emphasized that jamming signals would be largely ineffective against advanced drones.
“There is not much you can do other than shoot them down or using some kind of kinetic impact, drone-on-drone combat basically,” he said.
The repeated incursions have drawn comparisons to similar incidents in Poland, Romania, and Estonia, where Russian fighter jets violated allied airspace.
These events occur amid Russia’s ongoing invasion of Ukraine, heightening regional security concerns. Justice Minister Peter Hummelgaard announced plans to explore additional measures, including legislative changes allowing infrastructure owners to neutralize drones actively.
According to North Jutland police, the Wednesday night sightings mirrored the pattern observed during Copenhagen’s Monday shutdown, with multiple drones observed flying with lights on.
Frederiksen described the Copenhagen incursion as the “most serious attack on Danish critical infrastructure to date,” signaling the growing threat of hybrid warfare targeting civilian and military installations alike.
Experts warn that hybrid threats, including drone incursions, are becoming a permanent feature of modern conflict. The blend of civilian technology, such as commercial drones, with potentially hostile intent, poses unique challenges for national security. Poulsen noted, “The threat from hybrid attacks is here to stay,” emphasizing the urgent need for coordinated defense measures across Europe.
The proposed “drone wall” initiative aims to integrate detection systems, rapid response protocols, and potential kinetic countermeasures.
While the specifics remain under discussion, the concept envisions a multi-layered defense network capable of identifying and neutralizing aerial threats before they reach sensitive sites. Funding from the EU’s Security Action for Europe loans scheme could support procurement, research, and cross-border coordination.
The incidents have sparked a broader debate in Denmark and Europe about preparedness and technological investment. Critics have questioned why the drones were not immediately shot down, while officials argue that current capabilities are limited and evolving.
Poulsen noted that Denmark possesses a range of defensive tools but seeks to enhance them in response to increasingly sophisticated aerial threats.
NATO allies have underscored their commitment to supporting Denmark. Discussions are underway regarding the integration of early-warning radar systems, advanced counter-drone technology, and joint response strategies.
The incidents highlight vulnerabilities in both civilian and military airspace and underscore the necessity of international cooperation in mitigating hybrid attacks.
Public and political reactions in Denmark reflect concern and urgency. Lawmakers are calling for rapid legislative and technological responses to prevent future disruptions.
Security analysts suggest that these drone incursions may mark a new phase of low-intensity hybrid operations, designed to test responses and provoke political uncertainty without traditional military engagement.
The potential involvement of foreign actors, combined with the strategic targeting of multiple airports, underscores the geopolitical dimension of the threat.
While investigations continue, authorities maintain that all possibilities are being considered. The incidents have also prompted broader discussions about EU-wide defense capabilities and the role of NATO in protecting civilian infrastructure.
As Europe confronts these new aerial threats, experts emphasize that the challenge is not limited to Denmark. Commercial and military drones are increasingly accessible and sophisticated, raising the risk of similar incursions across the continent.
Collaboration between nations, investment in detection technology, and legislative reforms are seen as essential steps in safeguarding critical infrastructure.
Denmark’s airports have become the focal point of escalating drone threats, prompting urgent EU and NATO discussions. The temporary closures at Aalborg and other airports underscore the vulnerability of critical infrastructure to modern hybrid attacks.
With talks on the proposed “drone wall” scheduled for Friday, European leaders are seeking coordinated solutions to detect, neutralize, and prevent future incursions. The incidents highlight the evolving nature of security challenges in Europe and the need for robust, collaborative defense strategies.
