Moscow, Aug 2 (IANS): Two Russian MiG-31 fighter jets and an An-26 military plane, on a training flight over the Baltic Sea neutral waters, were "followed" by a NATO fighter jet, the Defence Ministry has said.

"While the Russian planes were flying over neutral waters of the Baltic Sea, North Atlantic Treaty Organisation F-18 fighter jet approached the Russian aircraft and followed them at a safe distance for about one minute. Later, it changed its course and flew away towards the airspace of the Baltic state," Xinhua news agency cited the ministry as saying.

NATO earlier said its fighter jets of the Baltic air-policing mission had intercepted three Russian planes over the Baltic Sea.

The Russian Defence Ministry has repeatedly said the flight of the aircraft was performed in strict compliance with the international rules of the airspace use and air border of other countries were not violated.

The number of air incidents involving Russian and NATO planes has increased over the past years since the US-led alliance ratcheted up its military presence on Russia's western border in 2014.