The Danish prime minister has said the country was subjected to the “most serious attack on Danish critical infrastructure to date” after a drone incursion shut Copenhagen airport for several hours.
Mette Frederiksen said authorities were still investigating who was behind the suspected hybrid attack, but she 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 on Monday night close to the airport, which is also the main airport for southern Sweden, 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 in Denmark came from multiple directions, turning their lights on and off for several hours before disappearing.
Oslo airport, Norway’s main aviation hub, was also forced to close for three hours after two drones were observed there.
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.
The Norwegian prime minister, Jonas Gahr Støre, accused Russia of violating Norwegian airspace three times in recent months.
Frederiksen said in a statement it was a reflection of “the times we live in and what we as a society must be able to handle”.
“The police assess that this is a capable actor and the Copenhagen police are working closely with PET [the Danish security and intelligence agency], the Danish armed forces and international partners on the investigation, which is in full swing,” she said.
“We are obviously not ruling out any options in relation to who is behind it. And it is clear that this fits in with the developments we have been able to observe recently with other drone attacks, violations of airspace and hacker attacks on European airports.”
She said in an interview it had to be seen “in the context of everything else that is happening in Europe”.
“We have seen drones over Poland that should not have been there, we have seen activity in Romania, violations of Estonian airspace, we have a hacker attack on European airports over the weekend and now drones in Denmark and Norway,” she told the Danish broadcaster DR on Tuesday morning.
“Therefore, I can only say that this is in my eyes a serious attack on Danish critical infrastructure.”
She said the incursion was intended to “disrupt and create unrest. To create concern. See how far you can go and test the limits.”
She added: “I cannot in any way deny that it is Russia. We are seeing a number of hybrid attacks and sabotage and attempted sabotage. What exactly has taken place in Denmark, the authorities are now investigating.”
Her Norwegian counterpart, Gahr Støre, said in a statement: “Russia has violated Norwegian airspace on three occasions this spring and summer.
“We cannot determine whether this was done intentionally or due to navigation errors. Regardless of the cause, this is not acceptable.”
He described the three Norwegian incidents this year as “smaller in scope” than those in Estonia, Poland and Romania, but they came after more than 10 years with no such incidents. He added: “They are nevertheless incidents that we view very seriously.”
Two of the incidents were over sea areas north-east of Vardø, which is close to the Norwegian border with Russia, and the third was in an uninhabited area along the land border in East Finnmark. Gahr Støre said the border violations lasted between one and four minutes. According to the Norwegian government, the first incident, on 25 April, involved a Russian SU-24 fighter jet; the second, on 24 July, involved a Russian L410 Turbolet aircraft; and the third, on 18 August, involved a Russian SU-33 fighter jet.
Separately, on Monday night, a couple from Singapore, tourists in their 50s and 60s, were reportedly arrested for flying a drone in central Oslo. The drone is being examined by authorities and there is no suspicion that it is related to the drone sightings at Oslo or Copenhagen airports.
Jens Jespersen, a Danish police chief superintendent, said of the airport drone incident: “We have concluded that this was what we would call a capable operator. It’s an actor who has the capabilities, the will and the tools to show off in this way.”
He said it was too early to say whether the incidents in Denmark and Norway were connected. The PST said it was working to establish whether the Norwegian and Danish drone sightings were related.
The Ukrainian president, Volodymyr Zelenskyy, claimed Russia was behind the Copenhagen incident. Danish police declined to comment on the claim, saying they did not know.
Among the theories being investigated by police is that the drones may have been launched from ships. Copenhagen airport is a short distance from the Baltic and one of the world’s busiest shipping lanes where hundreds of Russian shadow fleet ships are understood to be passing through carrying crude oil on which sanctions have been imposed.
Ursula von der Leyen, the president of the European Commission, said she had spoken to Frederiksen about the Copenhagen incident, writing on social media: “While the facts are still being established, it is clear that we are witnessing a pattern of ongoing challenges at our borders.”
Mark Rutte, Nato’s secretary general, said it was too early to say whether the incident in Denmark was connected to Russian violations of airspace elsewhere in Europe.
Troels Lund Poulsen, Denmark’s minister of defence, said the country “must be better equipped against drones”.
Copenhagen police said an “intensive investigation” was under way.
“Since yesterday [Monday] evening the Copenhagen police have been conducting an intensive investigation regarding the presence of unidentified drones over Copenhagen airport. The investigation is being carried out in cooperation with, among others, the police intelligence service, Danish defence, Copenhagen airport, Naviair, and other relevant authorities,” it said in a statement.
“There were several larger drones coming from different directions, and they also left the airspace over and around the airport in various directions. It is still too early to say where the drones came from, but based on the drones’ flight patterns, the Copenhagen police assess that one or more so-called ‘capable actors’ are behind the drone flights.”
Copenhagen diverted 31 flights to other airports, which led to 100 flights being delayed or cancelled, affecting about 20,000 passengers.
There have been a number of disruptions at European airports in recent days. On Friday, a cyber-attack on check-in and boarding systems led to problems at London Heathrow, Berlin and Brussels.
