From the moment the Russian pilots entered Estonian airspace, they were pursued by Nato’s most advanced fighter jets.

The planes' detection in international airspace off Alaska comes amid tensions over Russian incursions in NATO airspace.

The reason is a series of increasingly brazen incursions into NATO airspace. On September 8, 21 Russian drones entered Polish territory, where some of them were shot down by an unprecedented Polish-German-Italian-Dutch military operation.

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,

Officials say defending against drones is complex and requires affordable technology which can be quickly mass produced

Russian drones are now targeting Nato members. As Russia is running out of troops, Russia's hybrid war is not just cost-effective; it's also a necessity.

Authorities didn't immediately assign blame Tuesday for the two to three large drones that shut Copenhagen Airport.