"According to preliminary information, the cause of the crash of the two fighters was pilot error," Alexander Drobyshevsky said.
Two MiG-29s collided 40 kilometers (25 miles) from the Millerovo airfield, which is located some 220 kilometers (130 miles) from the regional center Rostov-on-Don, during a planned flight.
Both pilots survived the crash, one with slight facial lacerations, and no injuries or damage was reported on the ground.
The spokesman also said that the aircraft did not carry any combat payload at the time of the crash.
A team of military investigators has been dispatched to the crash site to probe the causes of the accident and the Military Prosecutor's Office of the North Caucasus Military District has opened a criminal investigation into the collision.
The MiG-29 Fulcrum is as a single-seat fighter-interceptor with excellent maneuverability and basic ground attack capability.
It was one of the Soviet Union's most important combat aircraft in the last years of the Cold War, and remains an important asset for the Russian Air Force. The aircraft has been exported to 27 countries, and is being updated with improved avionics and electronics to keep it in service well into the 21st century.
