Unidentified drones flew over Danish military sites including its biggest base during the night, the latest in a slew of sightings officials have called a "hybrid attack" and hinted at possible Russian involvement.
Drones were spotted at "several military sites", a Danish military spokesman told AFP, refusing to provide other details.
Police said "one to two drones" were observed yesterday at around 8.15pm local time near and over the Karup military base, the country's biggest base which houses all of the armed forces' helicopters, airspace surveillance, flight school and support functions.
Karup is also home to parts of the defence command, according to the military's website.
Police spokesman Simon Skelkjaer said police could not comment on where the drones came from, adding: "We didn't take them down."
Police were cooperating with the military in their investigation, he said.
The Karup base shares its runways with the Midtjylland civilian airport, which was briefly closed though no flights were affected as none were scheduled at that hour, Mr Skelkjaer said.
Mysterious drone observations across the Scandinavian country since Monday have prompted the closure of several airports.
Drone reports also closed Oslo airport for several hours earlier in the week, following drone incursions in Polish and Romanian territory and the violation of Estonian airspace by Russian fighter jets, which raised tensions in light of Russia's ongoing invasion of Ukraine.
Danish Prime Minister Mette Frederiksen said on Thursday that "over recent days, Denmark has been the victim of hybrid attacks," referring to unconventional warfare.
Investigators have so far failed to identify those responsible, but Danish Defence Minister Troels Lund Poulsen said that the flights appeared to be "the work of a professional actor".
Ms Frederiksen has pointed the finger at Russia.
"There is one main country that poses a threat to Europe's security, and it is Russia."
Moscow said it "firmly rejects" any suggestion that it was involved in the Danish incidents. Its embassy in Copenhagen called them "a staged provocation", in a post on social media.
Danish Justice Minister Peter Hummelgaard said earlier this week the aim of the attacks was "to spread fear, create division and frighten us".
The drone flights began just days after Denmark announced it would acquire long-range precision weapons for the first time, as Russia would pose a threat "for years to come".
Hummelgaard said Copenhagen would also acquire new enhanced capabilities to detect and neutralise drones.
Defence ministers from around ten EU countries agreed yesterday to make a so-called "drone wall" a priority for the bloc.
EU Defence Commissioner Andrius Kubilius said Europe needs to learn from Ukraine and swiftly build anti-drone defences.
"We need to move fast," Mr Kubilius told AFP in an interview. "And we need to move, taking all the lessons from Ukraine and making this drone wall together with Ukraine."
Copenhagen will host an EU summit gathering heads of government on Wednesday and Thursday.
It said yesterday it had accepted Sweden's offer of its anti-drone technology to ensure the meeting could go ahead without disruption.
