Introduction — What Happened?
In the second half of September 2025, Denmark became the scene of a series of incidents involving unidentified drones that appeared over civilian airports and military bases.
The most spectacular event took place on September 22, when drones disrupted operations at Copenhagen’s Kastrup Airport — the facility was shut down for several hours, with more than 100 flights delayed or canceled.
In the following days, similar sightings were reported at Aalborg, Esbjerg, Sønderborg airports, and over the Skrydstrup military base.
The Danish government and security services openly admit they treat these events as more than isolated incidents — describing them as a possible hybrid attack.
Key Aspects of the Incidents
Characteristics of the Sightings
- The drones were described as relatively large and professionally operated — their maneuvers and time spent over airspace suggested advanced operators.
- In many cases, drones left the airport zone on their own (without confrontation with air defense forces).
- The incidents occurred after dark, making visual monitoring and response particularly difficult.
Scale and Consequences
- The temporary closure of Copenhagen Airport caused significant disruptions to air travel — rerouted flights, delays, and cancellations.
- These incidents forced Danish authorities to raise security readiness and coordinate monitoring and threat analysis.
- Denmark called for support and cooperation from NATO and the European Union.
- NATO pledged to boost its presence in the Baltic Sea region — deploying additional surveillance systems, radars, and the “Baltic Sentry” operation to protect critical infrastructure.
- With Denmark holding the EU presidency and preparing to host a European summit in Copenhagen, a temporary ban on civilian drone flights was introduced (except for emergency services).
Hypotheses and Possible Perpetrators
- Danish Defense Minister Troels Lund Poulsen called the events a systematic operation — “there is no doubt everything points to a professional actor.”
- However, no conclusive evidence has been presented pointing to a specific country. Denmark has not ruled out Russian involvement, although the Kremlin consistently denies responsibility.
- Some analyses suggest drones may have been launched from offshore platforms — such as ships acting as mobile control stations.
- In the broader context of European security and the war in Ukraine, these events align with the growing trend of using drones as tools of strategic pressure and hybrid warfare.