Drones that forced airport closure may have been Russian - Danish PM

The Danish prime minister has said her country suffered the "most serious attack on Danish critical infrastructure to date" after a drone incursion shut Copenhagen airport for several hours on Monday night.

- Miranda Bryant

Mette Frederiksen said authorities were still investigating who was behind the suspected hybrid attack, but said she could not rule out Russia.

Moscow has denied any involvement. The Kremlin's spokesperson, Dmitry Peskov, accused Frederiksen of making "unfounded accusations".

Danish police said two or three large drones that were seen close to the airport appeared to have been flown by a "capable operator" who was looking to show that they had particular capabilities. No suspects have so far been identified.

The drones came from multiple directions, police said, turning their lights on and off for several hours before disappearing.

Oslo airport, Norway's main hub, was also forced to close for three hours after two drones were observed there. The Norwegian prime minister, Jonas Gahr Støre, accused Russia of violating Norwegian airspace three times in recent months.

Tens of thousands of passengers were stranded in the Nordic region by the two incidents and flights had to be diverted. Authorities in Denmark and Norway are investigating whether the two sightings were related.

Frederiksen said it was a reflection of "the times we live in and what we as a society must be able to handle".