Danish police said drone activity in Aalborg airspace similar to drones that shut down Copenhagen airport earlier this week.

Denmark’s Aalborg airport, which is used for commercial and military flights, was closed due to unidentified drones operating in its airspace, a closure that follows just days after the country’s main Copenhagen airport was forced to shut temporarily due to drone sightings.

Danish police said early on Thursday that “more than one” drone was sighted near Aalborg airport, which is located in northern Denmark, in the Jutland region, and is the country’s fourth-largest city by population.

Police said the drone sightings in Aalborg followed a similar pattern to the drones that halted flights at Copenhagen airport for four hours on Monday, when a number of large and unidentified drones were spotted near what is one of Scandinavia’s busiest airports.

The closure of Aalborg airport affected Denmark’s armed forces because it is used as a military base, police said.

“It is too early to say what the goal of the drones is and who is the actor behind,” a police official told the Reuters news agency, adding that authorities would take down the drones if possible.

The Danish armed forces said they were assisting local and national police with the investigation, but declined to comment further.

Police said later on Thursday morning that the drones had left Aalborg airspace but that drones were also reported in the vicinity of airports in the towns of Esbjerg, Sonderborg and Skrydstrup in the west of the country.

Fighter Wing Skrydstrup in southern Jutland is the base for Denmark’s F-16 and F-35 fighter jets.

De uidentificerede droner som blev observeret i det nordjyske, befinder sig ikke længere over luftrummet ved Aalborg Lufthavn. En intens efterforskning er gået i gang, og politiet beder alle med oplysninger i sagen henvende sig på telefon 114. #politidk https://t.co/sU3Azw8amD

— Nordjyllands Politi (@NjylPoliti) September 25, 2025

Translation: The unidentified drones that were observed in northern Jutland are no longer in the airspace over Aalborg airport. An intensive investigation has been launched, and the police ask everyone with information about the case to contact them on phone 114.

Northern Jutland police told reporters that “more than one drone” had been sighted near Aalborg airport, and they were flying with lights on.

The drones were first sighted at about 9:44pm local time [19:44 GMT] on Wednesday, according to police, and remained in the airspace for several hours.

Eurocontrol, which oversees European air traffic control, said arrivals and departures at Aalborg airport would be at a “zero rate” until 04:00 GMT on Thursday due to drone activity in the vicinity.

Northern Jutland police said they could not specify the type of drones or whether they were the same as the ones flying over Copenhagen airport on Monday.

Authorities in Denmark said the incident at Copenhagen airport was the most serious attack yet on its critical infrastructure and linked it to a series of suspected Russian drone incursions and other disruptions across Europe.

Authorities in Norway also shut the airspace at Oslo airport for three hours on Monday evening after a drone was sighted.

Speaking on Tuesday, Danish Prime Minister Mette Frederiksen said she “cannot reject in any way that it could be Russia” that was behind the Copenhagen airport incident.

Ursula von der Leyen, the president of the European Commission, said on social media that “while the facts are still being established, it is clear we are witnessing a pattern of persistent contestation at our borders”.

“Our critical infrastructure is at risk,” she said. “And Europe will respond to this threat with strength and determination.”

Kremlin spokesperson Dmitry Peskov called any allegations linking Russia to the drones “unfounded”, saying that Russian “aircraft are guided by international regulations in all their flights and do not violate them in any way”.

Earlier this month, Poland closed four of its airports, including one in its capital, Warsaw, after Russian drones repeatedly violated Polish airspace, according to the Polish military.

NATO members have committed to increasing the defence of their borders while reconfirming their allegiance in the aftermath of the drone incident in Poland.