At least 15 flights have been diverted as the airport remains closed until the situation is resolved, officials in Denmark say.

Authorities in Denmark have closed Copenhagen airport after unidentified drones were sighted nearby, causing about 15 flights to be diverted, police and airport officials told the AFP news agency.

“The airspace over Copenhagen airport has been closed since 8:30pm (18:30 GMT) due to two to three unidentified drones. No aircraft can take off or land,” airport spokeswoman Lise Agerley Kurstein said.

She said about 15 flights had been diverted to other airports.

Copenhagen police, meanwhile, said that “three or four big drones” had been observed flying over the airport.

“They are still flying back and forth, coming and going,” duty officer Anette Ostenfeldt told the AFP at 10:45pm (20:45 GMT), adding that police were at the airport investigating.

She could not say if the drones were military or civilian.

“But they are bigger than what you as a private individual can buy,” Ostenfeldt said.

Airport officials said the airport would remain closed until the situation was resolved. “We currently have no timeline for reopening,” Kurstein, the airport spokeswoman, said.

The incident comes as several European countries have reported violations of their airspace by Russia. Estonia said on Friday that three Russian MiG-31 fighter jets had entered Estonian airspace without permission.

During a Russian air strike on Ukraine the week before, Poland said about 19 drones flew into its airspace. The Polish Air Force and NATO allies shot down some of the unmanned vehicles, marking the first time Russian drones were downed over NATO territory since Moscow’s full-scale invasion of Ukraine in 2022.

Romania also registered a Russian drone in its airspace.

The United Nations Security Council (UNSC) convened on Monday to address the issue of airspace violations.

Russia’s ambassador to the UN, Dmitry Polyanskiy, denied the allegations that Moscow’s fighter jets had violated the airspace of neighbouring Estonia, saying that last Friday’s flight of three of its MiG-31 aircraft was done “strictly in accordance with international airspace regulations”.

The Russian Ministry of Defence echoed his remarks, saying that “objective monitoring” confirmed that the MiGs did not breach Estonian borders.

NATO allies at the UNSC meeting condemned Russia for violating the alliance’s airspace.

“Your reckless actions risk direct armed confrontation between NATO and Russia. Our alliance is defensive, but be under no illusion we stand ready to defend NATO’s skies and NATO’s territory,” the United Kingdom foreign secretary, Yvette Cooper, said.

NATO’s North Atlantic Council will meet to discuss the issue on Tuesday.