Denmark's Defence Minister, Troels Lund Poulsen and the Minister of Justice, Peter Hummelgaard, attend a press conference at the Ministry of Defence in Copenhagen, Denmark, September 25, 2025. The Minister of Defence and the Minister of Justice provide an update on the recent drone activities at several airports in Denmark. Ritzau Scanpix/Emil Helms/via REUTERS
Denmark's Defence Minister, Troels Lund Poulsen and the Minister of Justice, Peter Hummelgaard, attend a press conference at the Ministry of Defence in Copenhagen, Denmark, September 25, 2025. The Minister of Defence and the Minister of Justice provide an update on the recent drone activities at several airports in Denmark. Ritzau Scanpix/Emil Helms/via REUTERS
Denmark's Minister of Defence, Troels Lund Poulsen, Minister of Justice, Peter Hummelgaard, Chief of Police, Thorkild Fogde and Chief of Defence, Michael Hyldgaard, hold a press conference at the Ministry of Defence in Copenhagen, Denmark, September 25, 2025. The Minister of Defence and the Minister of Justice provide an update on the recent drone activities at a number of airports in Denmark. Ritzau Scanpix/Emil Nicolai Helms/via REUTERS
Denmark's Defence Minister, Troels Lund Poulsen and the Minister of Justice Peter Hummelgaard attend a press conference at the Ministry of Defence in Copenhagen, Denmark, September 25, 2025. The Minister of Defence and the Minister of Justice provide an update on the recent drone activities at several airports in Denmark. Ritzau Scanpix/Emil Helms/via REUTERS
Denmark's Justice Minister Peter Hummelgaard attends a press conference at the Ministry of Defence in Copenhagen, Denmark, September 25, 2025. The Minister of Defence and the Justice Minister provide an update on the recent drone activities at a number of airports in Denmark. Ritzau Scanpix/Emil Helms/via REUTERS
Vehicles are parked at Aalborg Airport, in Aalborg, Denmark, September 25, 2025. Drones were observed over the airport on Wednesday evening and during the night to Thursday, and the airspace over Aalborg Airport was closed. Ritzau Scanpix/Bo Amstrup/via REUTERS
Aalborg Airport, following the observation of drones over the airport on Wednesday evening and the night to Thursday, the airspace over Aalborg Airport was closed, in Aalborg, Denmark, September 25, 2025. Ritzau Scanpix/Bo Amstrup/via REUTERS
A light moves in the sky over Aalborg, amid reports of drone sightings that led to the city's airport, used for commercial and military flights, being closed due to drones in its airspace, in Aalborg, Denmark, September 24, 2025, in this screengrab taken from social media video. Morten Skov/@MSchieller69609/via REUTERS
FILE PHOTO: An officer walks next to vehicles following the temporary closure of airspace late on Monday after drones were observed in Danish airspace, in Copenhagen, Denmark, September 23, 2025. Ritzau Scanpix/Steven Knap/via REUTERS/ File Photo

COPENHAGEN (Reuters) -Denmark said on Thursday that drone incursions that briefly shut two of its airports and affected military installations overnight were hybrid attacks intended to spread fear, but said it did not know who was behind them.

The incidents are just the latest in a series of drone incursions - including two days ago in Denmark - over the past few weeks that have exposed the vulnerability of European airspace and the challenges governments face in countering them.

Poland shot down suspected Russian drones in its airspace on September 10. Danish authorities said on Thursday they decided not to take down any of the drones in its airspace for safety reasons, despite the disruption caused to air traffic.

AALBORG AIRPORT SHUT FOR THREE HOURS

Billund airport, Denmark's second biggest, was closed for an hour, and Aalborg airport, used for commercial and military flights, was closed for three hours due to the drone incursions late on Wednesday, Danish police said.

Both had reopened on Thursday morning.

Drones were also observed overnight near airports in Esbjerg and Sonderborg, as well as Skrydstrup airbase, home to some of Denmark's F-16 and F-35 fighter jets, and over a military facility in Holstebro, police told Reuters.

All affected locations are on the Jutland peninsula in western Denmark.

"It certainly does not look like a coincidence. It looks systematic. This is what I would define as a hybrid attack," Danish Defence Minister Troels Lund Poulsen told reporters, adding that the country was facing no direct military threat.

Local resident Morten Skov told Reuters he saw green blinking lights coming from west of Aalborg airport, which "stood still right over" the facility.

In a video shared with Reuters by Skov, light is seen moving away from the airport toward the west.

Danish national police said the drones had followed a similar pattern to those that halted flights at Copenhagen airport late on Monday and early Tuesday.

DENMARK HAS POINTED FINGER AT RUSSIA

Prime Minister Mette Frederiksen described the incident at Copenhagen airport as the most serious "attack" yet on Denmark's critical infrastructure and linked it to a series of suspected Russian drone incursions and other disruptions across Europe, without giving evidence.

Russia's ambassador to Denmark, Vladimir Barbin, denied any involvement by his country in the Copenhagen incident. Russia has not commented on the latest drone incidents over Jutland.

Poulsen said the government had not yet decided whether it would request consultations under NATO's Article 4. Under that article of the military alliance's founding treaty, members can bring any issue of concern, especially related to security, for discussion, allowing more time to determine what steps to take.

Poland invoked Article 4 earlier this month after downing the drones over its territory, in what Polish Prime Minister Donald Tusk said was a "large-scale provocation" by Russia. Moscow said it had not planned to hit any targets in Poland while conducting drone attacks on nearby western Ukraine.

The latest drone incursions in Denmark come just a week after Copenhagen said it would acquire long-range precision weapons to counter the threat posed to Europe by Russia, in what Frederiksen said was a "paradigm shift in Danish defence policy".

Denmark's recent initiatives to boost its military spending have drawn sharp criticism from Russia, including plans to host Ukrainian missile fuel production near the Skrydstrup airbase.

(Reporting by Jacob Gronholt-Pedersen, Stine Jacobsen, Maria Laguna, Søren Sirich Jeppesen, Anna Ringström and Terje Solsvik; Editing by Gareth Jones)