State television reported the incident happened on the road between the eastern town of Pirot, near the border with Bulgaria, and Nis, in southern Serbia.
ADVERTISEMENTA van carrying some 50 migrants overturned on Friday in southwestern Serbia, injuring more than 30, according to the country's state television.
Video footage on RTS showed an overturned van by the side of the road and police directing traffic.
No other details were immediately available and Serbia's police have not issued an official statement.
Serbia lies on the so-called Balkan land route of migration, where people smugglers often facilitate illegal border crossings for people seeking to reach Western Europe.
Migrants come to Serbia from Bulgaria or North Macedonia and then travel north and west toward Hungary or Croatia, often crammed in vans or cars.