Finland, Estonia, Latvia, Lithuania and Poland have been working on a drone wall project, but in March, the European Union’s executive branch rejected a joint Estonia-Lithuania request for funds to set one up.

European defence ministers and Ukraine held urgent talks on Friday over plans for a so-called “drone wall” to defend NATO’s eastern flank amid an alarming rise in Russian incursions and unidentified drone flights testing European airspace.

Russia launched out a series of drone attacks on the Ukrainian city of Sumy on Thursday night, causing fires in multiple locations. Meanwhile Ukraine has once again targeted Russian infrastructure, including an oil refinery in Krasnodar Krai.

Denmark said that a spate of unidentified drones in its airspace that have shuttered airports was the work of professionals rather than amateur actors.

Several unidentified drones shut down airspace over Copenhagen Airport on Monday night, prompting concerns that Russia could be behind the flyover above Scandinavia’s largest airport. The incident caused a major disruption to air traffic in and out of the airport.

Germany said Thursday it would step up its defences -- from drone warfare to outer space -- at a time of growing tensions between Russia and NATO while the Ukraine war grinds on.Defence Minister Boris Pistorius said Thursday that Germany would spend 35 billion euros ($41 billion) on outer space defence by 2030,

Polish President Karol Nawrocki has expressed dissatisfaction with comments made by his Ukrainian counterpart Volodymyr Zelenskyy regarding the shooting down of Russian drones over Poland. Source: Nawrocki in an interview with Polish news outlet Fakt,

It wasn’t immediately clear who was behind the flyover. But Denmark’s prime minister and NATO’s secretary-general said Tuesday that Russian involvement couldn’t be ruled out.