Copenhagen and Oslo main international airports hours out of service, sightings over more airports and an air force base in Denmark, plus the main Swedish naval base of Karlskrona. It is the week of the mysterious big drones flying over Scandinavia.
The latest sighting of the bigger drones is from the Karlskrona archipelago on the night from 25 to 26 September 2025. Near the Möcklösund bridge, civilian eyewitnesses and later alarmed police officers confirmed drones in the air. The bridge is located less than 10 kilometres (5.8 miles) east of the main base of the Swedish navy.
Drones over Copenhagen and Oslo
According to the Swedish police, the drones seem to have had a similar size as at least four drones that flew over Copenhagen International Airport (Kastrup) on Monday 22 September. Because of the drones, the authorities shut down the airport—Scandinavia’s main air hub—for over 4 hours. Danish police decided not to shoot down or jam the drones, as they said they were afraid falling drones would either hurt somebody on the ground or would hit sensitive fuel storage tanks. At least two similar drones were also observed Monday night over Olso-Gardermoen International Airport, about 3.5 hours after the air alarm over Kastrup, causing a shut-down and diverting flights during two hours.
Flights diverted
Flights inbound to Kastrup and Gardermoen had to divert all of a sudden, including a SAS Scandinavian Airlines flight from Hamburg to Copenhagen on final approach less than a kilometre (0.62 miles) from the runway. At almost 20:30 local time, this flight SK652 was the first plane to divert, and it landed safely at Malmö-Sturup airport in Sweden, 45 kilometres (28 miles) further east.
Drones over Aalborg and Skydstrup Airbase
Wednesday 24 September, fixed-wing drones from unknown origin were again spotted over Denmark. This time, Aalborg airport had to close down for over 3 hours, causing three planes to divert to nearby airports. In all cases, the drones seemed to have been flying with their red, green and white navigation lights on. The Danish police also received reports of drones on Wednesday over Esbjerg, Sønderborg, Skrydstrup Airbase, and the army base of Holstebro.
Origin unknown
Although the origin of the drones has not been made public, but many speculate it could be Russia and that they could have been used to create panic, and as a show of force to NATO countries in Scandinavia which openly support Ukraine with training of its military, and with weapons and other products and services.
“A state” is behind it
Danish Prime Minister Mette Frederiksen called the drone flights “the most serious attack on Danish infrastructure till now”. The Danish government believes “a state” is behind it. The Norwegian government stated it was not certain yet if its aerospace was violated on purpose or if the drones made a “navigation error”.
Danish police and navy
On Thursday 25 September, the Danish police confirmed all its personnel has been place at a higher state of alert—similar to when there would be a terror attack or a state visit. The Danish radio (DK) reported that the Royal Danish Navy frigate Esbern Snare was observed patrolling the waters near Copenhagen, but the Danish armed forces have chosen not to comment on the deployment.
The unknown drone incursions into Scandinavian and NATO aerospace has not caused any casualties, nor did they drop any objects. There is no evidence the drones were armed. | © 2025 Marcel Burger, nordicreporter.com. Featured photo: Copenhagen International Airport in 2019 (Photo: Kallerna (CC))