"In the Republic of North Ossetia-Alania, in a mountainous area, a Su-34 aircraft of the Russian Aerospace Forces crashed during a scheduled training flight," Russia's RIA state news agency cited the defense ministry as saying, Reuters reported.
"The plane crashed in a deserted area. There is no destruction on the ground. The crew was killed."
It was not immediately known how many people were on board.
The Sukhoi Su-34 is a Soviet-origin Russian all-weather supersonic medium-range fighter-bomber aircraft.