New unidentified drones were observed over Denmark's biggest military base on Saturday, police said, in a slew of sightings that Danish officials have called a "hybrid attack".

Unidentified drones were observed during the night overDenmark's biggestmilitarybase, police said Saturday, the latest in a slew of sightings that Danish officialshave called a "hybrid attack".

The mystery drone observations have prompted theclosure of several airportsacross the Scandinavian country since Monday, when the first drones appeared.

"I can confirm that we had an incident around 8:15pm (1815 GMT Friday) that lasted for some hours. One to two drones were observed outside and over the airbase," duty officer Simon Skelsjaer told AFP, referring to the Karup military base.

He said police could not comment on where the drones came from, adding: "We didn't take them down."

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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 no commercial flights were scheduled at that hour, Skelsjaer said.

Danish Prime Minister Mette Frederiksen said Thursday that "over recent days, Denmark has been the victim of hybrid attacks", referring to unconventional warfare.

(FRANCE 24 with AFP)

Originally published on France24