Russia's MiG-31 fighter jet was scrambled to intercept a Royal Norwegian Air Force plane over the Barents Sea, the National Defence Management Centre said.
The jet did not let the Norwegian aircraft violate the Russian border, it added.
"On August 25, Russian air control systems detected an air target approaching the Russian state border over the neutral waters of the Barents Sea. ... a MiG-31bm fighter from the air defence forces of the Northern Fleet was scrambled," the statement says.
The crew of the Russian fighter from a safe distance identified the object as a basic patrol aircraft R-3C Orion of the Royal Norwegian Air Force.
"After the foreign military aircraft turned away from the Russian state border, the Russian fighter returned safely to the home base. The entire flight of the Russian fighter MiG-31bm was conducted strictly in accordance with international rules for the use of airspace," the statement says.
On Monday, Russia's Sukhoi Su-27 fighter jet was scrambled to intercept military aircraft from the US, Germany and Sweden over the Baltic Sea.
