Russia on Saturday said a water-dropping plane carrying eight people had crashed in Turkey during a firefighting mission.
The Russian defence ministry said the Be-200 plane went down around 1330 GMT and that on board were five Russian servicemen and three Turkish citizens, Moscow news agencies reported.
It did not clarify if there were any survivors.
The plane crashed near the southern city of Adana, it said.
Russian consular representatives and a defense ministry commission were on their way to the crash site.
In July, Russia said it would send Be-200 planes to Turkey to help it fight spreading wildfires.
Turkish state news agency Anadolu reported that rescuers had rushed to the scene with television footage showing a column of smoke rising from a mountainous zone, adding it was unclear if the crew survived.