A Croatian fighter jet crashed on Tuesday during a training flight and a search for the crew is under way, the defence ministry said.
The Russian-made MiG-21 plane crashed around 2pm (1300GMT) in an uninhabited forested area near the eastern town of Slatina, the ministry said in a statement.
A rescue operation for the crew is ongoing, it said without elaborating.
Local media reported that one pilot managed to eject.
NATO and European Union member Croatia last year bought a batch of used Rafale planes from France, to replace its obsolete MiGs.
The first of the 12 Rafale planes are expected in Croatia by 2024.