Authorities in both countries are cooperating to determine if there was a link between the incidents

Major airports in Norway and Denmark have faced disruption after multiple drone sightings near runways caused widespread delays and cancelations on Monday and early on Tuesday.

In Denmark, police said two or three large drones were spotted around Copenhagen Airport, the busiest in the Nordic region. Airspace was closed at 8:30pm local time, halting all take-offs and landings. About 30 departures and 20,000 passengers were affected.

"The police have launched an intensive investigation to determine what kind of drones these are," Copenhagen police deputy assistant commissioner Jakob Hansen said. "The drones have disappeared and we have not taken any of them." A police spokesperson told CNN that as of 10:15pm, no arrests had been made.

The drones were last seen at 11:17pm, with airspace reopening at 12:20am on Tuesday. Airport officials warned that delays and cancelations would continue.

In Norway, Oslo Airport closed its airspace from midnight after a drone was spotted, a spokesperson for airport operator Avinor told Reuters. All departing flights were canceled or delayed, while arrivals were redirected to Gothenburg and Malmo in Sweden until the airport reopened at around 3:22am on Tuesday.

Hansen said police in Denmark and Norway are cooperating to see if the incidents are connected.

Media reports said Oslo Police earlier arrested two Singaporean nationals accused of flying drones over the Akershus Fortress, a medieval castle used for government events, but it was unclear whether the case could be connected to the airport disruption.

The incidents come just days after major European airports faced electronic check-in and boarding outages that caused widespread delays and cancelations from Friday through Sunday. London's Heathrow was hit, as well as airports in Berlin and Brussels, with 73 flights canceled. Several media outlets linked the issue to a cyberattack on service provider Collins Aerospace.

(RT.com)