Poland accused Russia on Friday of violating the "safety zone" of a Baltic Sea oil platform after two fighter jets flew low over the Petrobaltic installation.
The Polish Border Force said the military and other authorities were alerted following the incident, which it called a breach of security around the offshore site.
The breach came little more than a week after NATO aircraft shot down Russian drones over Poland, stoking fears the Ukraine war could spread beyond its borders.
The Baltic Sea incident came the same day Estonia summoned a Russian diplomat to protest what it called an "unprecedentedly brazen" airspace violation. The Foreign Ministry said three Russian fighter jets entered its airspace Friday without permission and remained for 12 minutes, the fourth such breach this