Denmark on Sunday ordered a ban on civil drone flights, after several unmanned aerial vehicles were witnessed at military facilities overnight, following a week in which drone sorties caused the temporary closures of several airports in the Nordic country.

The Danish military said it had deployed "several capacities" in response to the overnight drone sightings.

Earlier this week, drones forced Denmark to close its airports, including Copenhagen Airport, which was closed for nearly four hours on Monday.

Denmark has called the drones part of a "hybrid attack" but the government has stopped short of saying definitively who it believes is behind the missions.

Nevertheless, Danish Prime Minister Mette Frederiksen has said Russia is the main "country that poses a threat to European security."

"We are currently in a difficult security situation, and we must ensure the best possible working conditions for the armed forces and the police when they are responsible for security during the EU summit," Defense Minister Troels Lund Poulsen said in a statement on Sunday.

When will the drone ban be and why?

Civilian drones will be banned from Danish airspace from Monday through Friday of the coming week.

The Nordic country holds the rotating European Council presidency for the second half of 2025. Denmark will host EU leaders on Wednesday, followed by a summit on Thursday of the wider, 47-member European Political Community, set up to unite the bloc with other friendly European countries after Russia's 2022 full-scale invasion of Ukraine.

A German air defense frigate arrived in Copenhagen on Sunday to assist with airspace surveillance.

Is Russia behind the drone activity?

It is not clear who is behind the drone missions but Prime Minister Mette Frederiksen and NATO Secretary-General Mark Rutte have both said the notion of Russia being the perpetrator could not be ruled out.

Meanwhile, the Russian embassy in Denmark last week rejected claims of Moscow's involvement.

Edited by: Dmytro Hubenko