STORY: Video showed the wreckage of the plane scattered across what appeared to be a corn field on Sunday (July 17), with mangled parts of the plane still smoking.
Ukrainian-based airline Meridian, which operated the Antonov An-12, said all the crew members were killed in the crash.
State channel ERT reported that the pilot had requested an emergency landing due to an engine problem but the aircraft's signal was lost.
Serbia's defense minister said the plane was carrying 11.5 tonnes of products made by its defense industry and the buyer was Bangladesh defense ministry.
Local authorities, concerned over the contents of the cargo, advised residents to stay indoors and close their windows, according to ERT.
Witnesses said explosions could be heard from the burning plane after it crashed.