In a dramatic escalation of security concerns across Northern Europe, Denmark’s major airports have been repeatedly targeted by coordinated drone incursions, forcing closures, flight diversions, and raising fears of foreign interference. The incidents, which unfolded over consecutive nights in late September 2025, have put Danish and Norwegian authorities on high alert and triggered investigations involving multiple agencies, including the Danish Security & Intelligence Service (PET), Copenhagen police, and NATO warships.
On the night of September 22, Copenhagen Airport—the country’s largest and a crucial European hub handling nearly 30 million passengers annually—was abruptly shut down for almost four hours. According to Reuters, the closure came after large, blinking-light drones approached from several directions, prompting officials to suspend operations and disrupt approximately 150 flights. Danish authorities described the incident as the most serious attack yet on the nation’s critical infrastructure, with officials calling it both “professionally executed” and “provocative.”
The following evening, chaos rippled northward as Aalborg Airport, a key base for both commercial and military flights, was forced to close after drones were spotted in its airspace. Police confirmed the presence of up to three autonomous unmanned aerial vehicles (UAVs), again with their lights on, and swiftly suspended all arrivals and departures until 6:00 AM local time. At least four inbound flights—two SAS, one Norwegian, and one KLM—were diverted to other airports, and the departure board remained littered with cancellations and delays well into the next day. "The airspace over Aalborg Airport in Denmark has been closed after drones were spotted flying nearby," Aalborg Airport CEO Niels Hemmingsen told local media, echoing the sense of urgency and uncertainty gripping the region.
The incidents did not stop there. Drones were also observed near the airports in Esbjerg, Sønderborg, and Skrydstrup, with police forces across Denmark scrambling to verify and document each sighting. The pattern of these incursions—drones appearing at multiple sites, sometimes simultaneously—has led authorities to suspect a highly coordinated operation. As police stated on social media, "We are present and trying to verify the observations and document the incidents. We have no further information at this time, but will update here when there is new information."
Norway was not spared, either. On the same night as the Copenhagen attack, Oslo Airport was closed for three hours after drones were spotted overhead, raising the specter of a broader campaign targeting northern European airspace. Norwegian security authorities have since increased vigilance and are working closely with both national and international partners to monitor the evolving situation.
The search for those responsible quickly led Danish investigators to the sea. Three ships, all with links to Russia, emerged as key suspects in the Copenhagen incident. First among them is the Astrol 1 (IMO 9906544), a Russian-flagged coastal freighter sanctioned by the European Union. The vessel sailed through the Øresund Strait on the night of the attack, making unusual maneuvers that, according to Danish television reports, coincided with the drone activity. This put the Astrol 1 under intense scrutiny from authorities.
The second vessel, Pushpa (IMO 9332810), is a tanker sailing under the Benin flag but reportedly part of a Russian-linked "shadow fleet". It has changed names three times in two years and is falsely flagged in Malawi, a landlocked country with no legitimate maritime registry. NATO warships monitored Pushpa for four hours during the incident. Its dubious registration means the vessel cannot be properly insured—a detail that only deepens suspicions. Ukrainian sources have identified Pushpa as a frequent transporter of Russian oil, further tying it to Moscow’s interests.
The third suspect, Oslo Carrier 3 (IMO 9366146), is a Norwegian cargo ship that was located about seven kilometers from Copenhagen Airport during the attack. With a Russian-speaking crew and an owner with offices in Kaliningrad, Russia, its proximity and personnel have drawn the attention of investigators. Authorities have noted that the ship’s position during the incident was "suspicious."
Despite these leads, Danish officials acknowledge that proving direct involvement will be an uphill battle. As they explained, launch rails and drone control systems can be quickly removed, and personnel can shift between vessels to avoid detection. Similar tactics were reportedly used earlier in the month with the German cargo ship Scanlark, which was detained for suspected drone launches in August. Such cases, authorities say, require painstaking forensic work—no easy feat in the open sea.
Prime Minister Mette Frederiksen did not mince words about the gravity of the situation. She called the Copenhagen attack deliberate, stating it aimed to "disrupt and create unrest." Frederiksen also drew parallels to recent drone incursions in Polish and Romanian airspace, as well as Russia’s violation of Estonian airspace, signaling a pattern of increasingly aggressive behavior in the region. When pressed by reporters about Russian involvement, she conceded, "I cannot deny" that the drones were flown by Russia.
Russian officials, for their part, have flatly denied any connection. Vladimir Barbin, Russia’s ambassador to Denmark, insisted the incident "reveals a clear desire to provoke NATO countries into direct confrontation." This statement, reported by Reuters, reflects the deepening mistrust and rhetorical brinkmanship that now characterize relations between Moscow and its European neighbors.
The timing of the drone attacks could hardly be more fraught. Just days earlier, a cyberattack had disrupted operations at Heathrow and other major European airports, causing widespread cancellations and delays. While there is no official confirmation that the cyber and drone incidents are linked, their proximity has left many in the aviation industry deeply unsettled. European air traffic control authorities have warned that unmanned aerial systems present a growing threat, not just to individual airports but to the continent’s entire critical infrastructure.
In response to the Copenhagen incident, a Royal Danish Navy vessel was dispatched to patrol nearby waters, underscoring the seriousness with which the government is treating these events. Meanwhile, Danish police have vowed to investigate all possibilities, including the theory that drones are being launched from ships lurking just outside territorial waters.
For passengers and airlines, the consequences have been immediate and costly. Hundreds of flights have been delayed, diverted, or canceled across Denmark, with ripple effects felt throughout Europe. The closures at Copenhagen and Aalborg have disrupted business travel, tourism, and vital military operations. As of Thursday morning, the status of flights from Aalborg to destinations like Amsterdam, Copenhagen, Rhodes, and Oslo remained uncertain, with airport management and police providing regular updates but few concrete answers.
As the investigation continues, one thing is clear: the age of drone warfare and hybrid threats has arrived in Northern Europe. With critical infrastructure increasingly vulnerable to both physical and cyber attacks, governments and security agencies face a daunting challenge in keeping the skies—and the seas—safe.
The coming weeks will likely bring more developments, but for now, Denmark and its neighbors remain on high alert, determined to get to the bottom of a mystery that has upended their sense of security and exposed the fragile nature of modern air travel.
