Drones over four Danish airports prompt closure as investigation widens

Drones were spotted overnight over four Danish airports, including Aalborg in northern Denmark, Esbjerg, Sonderborg and the Skrydstrup air base, prompting authorities to close Aalborg for several hours. The airport closed to incoming and outgoing flights for multiple hours before reopening, with all arrivals and departures halted and inbound flights diverted to other airports as the incident unfolded. Police said the drones flew over a very large area for several hours, and they could not shoot them down at Aalborg. The operators remain at large, and the motive behind the sightings remains unclear as an investigation led by Denmark’s intelligence service PET and the armed forces continues.

Wednesday night’s sightings come in the context of earlier drone incursions in the region, including episodes near Copenhagen that disrupted about 100 flights and stranded roughly 20,000 passengers. Danish Prime Minister Mette Frederiksen called that episode the most serious attack on Danish critical infrastructure to date and said Russian involvement could not be ruled out. Former U.S. President Donald Trump urged NATO members to shoot down intruding Russian jets, and Britain’s Foreign Secretary Yvette Cooper described the incidents as provocative and reckless and said the UK was ready to act. Police inspector Jens Jespersen said the Copenhagen event showed signs of a sophisticated operation, noting the number, size, flight patterns and timing over the airport.

Esbjerg and Sonderborg airports were not closed because no flights were scheduled there during the window, police said, but the drones were seen with lights and tracked from the ground, and officials stressed they could not yet confirm the drones’ type or origin, or the motive. Authorities have said the drone activity may be linked to a broader testing of NATO defenses. Flemming Drejer, director of operations at PET, said Denmark faces a high threat of sabotage and that attackers may seek to provoke a reaction, rather than to cause immediate damage. He said the situation requires vigilance as investigators weigh several theories, including the possibility that the drones were launched from ships in the Baltic shipping lane near the main Danish airport.

Denmark's incidents come amid a wider pattern in Europe: authorities have reported drone activity in Poland and Romania, and Russian jets violated Estonia’s airspace, raising tensions as Moscow continues its invasion of Ukraine. Ukrainian President Volodymyr Zelensky referred to Russia's violation of NATO airspace in Copenhagen in a social media post. The incidents have prompted heightened vigilance among Western allies, with security services cautioning that a sophisticated, possibly state-linked campaign may be underway.

Separately, Oslo Airport in Norway closed and diverted flights after drones were spotted nearby, and two people were arrested in Oslo in connection with a drone operation near Akershus Fortress, which houses the headquarters of Norway’s armed forces and the defence ministry. Russia on Monday denied involvement in the Copenhagen incidents. Denmark’s main airport sits near a busy shipping lane used by vessels entering and leaving the Baltic Sea, a detail that has fueled authorities’ theories about potential drone launch points from ships or other mobile platforms. The episode underscores ongoing tensions as NATO allies monitor Russia’s actions amid the war in Ukraine.