Russia’s Defense Ministry said on Sunday that Russian warplanes prevented two U.S. strategic bombers from violating the state border over the Barents Sea.

After having detected an air target approaching the Russian borders, the military scrambled MiG-29 and MiG-31 fighter jets, the ministry said in a statement. The MiGs identified the planes as two U.S. В-52Н strategic bombers.

“As the Russian fighter jets approached, the American strategic bombers adjusted their flight course… and subsequently turned away from the state border of the Russian Federation,” the ministry said.

The Russian warplanes carried out the flight in compliance with international rules on the use of airspace over neutral waters, it added.

The Pentagon did not immediately respond to a Reuters request for comment outside of regular hours.

Russia has reported similar incidents before when its planes have confronted military aircraft from NATO countries flying close to its border at a time of acute tension over the war in Ukraine.