Denmark, Germany and Norway investigate new drone sightings

Police in Denmarkreported Saturday that drones of unknown origin had been detected over the country's largest military base, in the latest episode in a series of similar detections that the government called a "hybrid attack."

"I can confirm that we had an incident around 8:15 pm [local time] that lasted for some hours. One to two drones were observed outside and over the airbase," officer Simon Skelsjaer told AFP.

Skelsjaer was referring to the Karup military facility, which shares its runways with Midtjylland airport. That one had to close briefly, although no flights were affected because no commercial flights were scheduled.

The official said the drones were not shot down, and that he could not comment on the origin of the aircraft. He further assured that the police and the military are working together on the investigation.

Danish government takes aim at Moscow

Danish Prime Minister Mette Frederiksen said during the week that the country had been the victim of "hybrid attacks," referring to a form of unconventional warfare, pointing directly at the Kremlin. "There is one main country that poses a threat to Europe’s security, and it is Russia."

Moscow rejected any involvement in the incidents in Denmark. Its embassy in Copenhagen said the events had been staged  in a message posted on social media.

Danish Justice Minister Peter Hummelgaard said earlier in the week that the aim of the attacks was "to spread fear, create division and frighten us." He added that his country will gain new capabilities to detect and neutralize drones.

The drone flights began days after Denmark announced it would acquire long-range precision weapons for the first time, arguing that Russia would pose a threat in years to come.

Oslo and Berlin report new airspace violations

In the last hours, both Norway and Germany raised alarms over similar incidents.

In the former, authorities claimed to be investigating possible drone incursions near its largest military base, Orland.

Also on Saturday, German Interior Minister Alexander Dobrindt claimed that a "swarm" of drones had been detected in the north of the country.

"We are seeing a constant hybrid threat," the German minister said, assuring that he would revise security regulations to allow the military to shoot down drones. "What we are witnessing is an arms race -- an arms race between drone threats and drone defense," he argued. "We must prepare ourselves for this."

Shielding Europe's skies

Both the North Atlantic Treaty Organization (NATO) and the European Union (E.U.) expressed concern about the incidents in Denmark and similar incidents in other countries on the continent.

NATO Secretary General Mark Rutte maintained that the alliance was taking the incidents that happened during the week on Danish territory "very seriously." Speaking about incursions by both Russian aircraft and drones into the airspace of at least six alliance member countries, Donald Trump asserted that the offending vehicles should be shot down.

Poland and Estonia invoked Article 4 of the NATO Treaty, which calls for consultations among member countries if either feels threatened. Some analysts have pointed to a Russian strategy of attrition, taking advantage of the low cost of drones.

A dozen E.U. countries agreed on Friday that the creation of a "drone wall" should be a priority for the bloc. This was explained by European Commissioner for Defense Andrius Kubilius, who detailed that the system should include "detection, tracking, and interception" capabilities.