The Serbian Defense Ministry says two pilots were killed when their warplane crashed southeast of the capital, Belgrade.
Officials said the Yugoslav-made single-engine Super Galeb G-4 crashed on April 7 near the village of Slatina, about 50 kilometers from Belgrade during a routine training flight.
The ministry said the cause of the crash was not immediately known and that an investigation had been launched.
The Super Galeb G-4 is used for training, as well as military missions.
Serbia has 22 Galeb aircraft from the Yugoslavia era, but only nine are still in service, officials said. The plane that crashed was made in the 1980s, state media reported.
The Associated Press quoted witnesses as saying the jet was flying low over the area before diving toward the ground.