Another Danish airport has been forced to close due to drone sightings - with a minister calling it a "professional" operation designed to cause fear.
All flights from Aalborg - which also serves as a military base - were halted during the incident, which began just before 10pm on Wednesday and lasted until about 1am.
Police said more than one drone was seen and they were flying with lights on.
It's not known who was responsible or if they were the same ones that affected Copenhagen airport earlier this week, officers added.
Drones were also spotted overnight near airports in the Danish towns of Esbjerg, Sonderborg and Skrydstrup.
Defence minister Troels Lund Poulsen said on Thursday morning the "systematic" flights appeared to be the work of a "professional actor".
"This is what I would define as a hybrid attack," he added.
The flights were designed to sow fear and division, added justice minister Peter Hummelgaard.
He said Denmark would get new capabilities to neutralise drones and put forward laws to allow airports to shoot them down.
Aalborg runs commercial flights but also hosts the army's special operations command, its maritime special operations force and its naval dog sled patrol.
Skrydstrup is also the base for Denmark's F-16 and F-35 fighter jets.
On Monday night, Norwegian authorities also shut airspace at Oslo Airport for three hours after a drone sighting.
Denmark's national police commissioner, Thorkild Fogde, said many people around the country had reported drones since the disruption in Copenhagen on Monday.
"Of course, many of these reports do not cover activities that are of interest to the police or the military, but some of them do, and I think the one in Aalborg does," he said.
The country's prime minister said earlier this week that Russia may be responsible for the Copenhagen incident.
Mette Frederiksen called the incident at Copenhagen airport the most serious attack yet on its critical infrastructure
"I certainly cannot deny in any way that it is Russia," she told public broadcaster DR.
Appearing to reference drone incursions in Poland and Romania, she said it was "clear that this fits in with the developments we have observed recently with other drone attacks, violations of airspace, and hacker attacks on European airports".
Kremlin spokesman Dmitry Peskov has rejected the allegations.
The drone sightings come after NATO jets were scrambled last week when Russian jets violated Estonian airspace.
(c) Sky News 2025: Denmark's Aalborg airport closes after drones spotted - as minister says 'professional actor' trying to cause fear<