Denmark's Aalborg airport in the north has been closed after unauthorized drones were seen in its airspace, according to local authorities.

Three other smaller airports in the south — Esbjerg, Sønderborg, and Skrydstrup — reported drone activity but remained open.

The incident follows a similar closure of Copenhagen's airport earlier this week due to a drone incursion, described by the prime minister as 'the most severe attack on Danish infrastructure so far.'

Police stated the drones were visible from the ground and are investigating the operators' motives, with a possibility of the incidents being a prank.

At least three flights were diverted from Aalborg, which also serves as a military base for the Danish Armed Forces. The North Jutland Police have been closely monitoring the situation without confirming the number of drones involved.

Chief Inspector Jesper Bøjgaard Madsen mentioned, We cannot yet comment on the purpose of the drones flying in the area, nor can we say anything about who the actor behind it is. He added that if opportunities arise, authorities would attempt to take down the drones.

While police do not believe there is an immediate danger to passengers or residents, they advised the public to stay clear of the area. Regarding the drone activity at Esbjerg, Sønderborg, and Skrydstrup, police took the reports seriously but could not comment on any perceived motives.

Flights from Aalborg included two returning to Copenhagen and one to Karup. The air traffic authority declared that all arrivals and departures at the airport would be suspended until 06:00 local time on Thursday.

This marks the second airport shutdown due to drone sightings in Denmark this week, with Prime Minister Mette Frederiksen emphasizing the serious implications these actions have.

The possibility of Russian involvement has been raised, although Kremlin spokesperson Dmitry Peskov dismissed these claims as 'unfounded.' This is amidst heightened tensions across Europe regarding airspace security and incursions by Russian aircraft.

Following recent drone incidents across various countries, NATO issued a stern warning to Russia, emphasizing that the alliance would utilize all available tools to ensure collective security.