Serbian authorities seized more than 160 kilograms (353 pounds) of heroin.
The drugs were discovered in a truck with Turkish registration plates, which was entering Serbia from Bulgaria, the customs officers said.
They said the street value of the heroin was estimated at 5 million EUR(US$7 million).
Balkans is a key route for smuggling of heroin and other drugs to Western Europe.
Russia has delivered three divisions of anti-aircraft missile systems S-300PM-2 to Syria. These systems differ from the classic S-300