NATO and Spain had to scramble jets to steer off two Russian Blackjack bombers which had flown into Spanish territory.
Spain sent two F-18 fighters to intercept the Russian planes north of Bilbao before the bombers turned around and flew north.
Norway, the UK and France were also forced to send their jets to intercept the TU-160 planes, as they skirted the airspace of each country.
Spanish media say it is the furthest south such an operation has had to take place.
The skirmish occurred on September 22 but news of the event has only been released today by the French Ministry of Defence.
It comes as relations between the West and Russia remain at a low and continue to fray over Syria.
The frequency of Russian bombers having to be intercepted by NATO planes is said to have increased dramatically over the last few years.