Russia's involvement in drone sightings [that closed Copenhagen airport for four hours] cannot be ruled out, Danish PM says: "the most severe attack on Danish infrastructure so far"

The Danish PM made a link between last night's events in Denmark and the recent Russian drone incursions in Poland and Romania, as well as the violation of Estonian airspace by Russian fighter jets.

Frederiksen said that the motive for the incursion in Copenhagen had likely been to "disrupt, create unrest... to see how far you can go and test the limits."

Danish intelligence mirrored this assessment, saying the country was facing a "high threat of sabotage".