Serbian police say a car carrying at least 12 migrants crashed on a highway, killing two Afghan nationals and injuring 10 other passengers, including five children.
Police said the suspected people smuggler who was driving the car fled the scene of the crash.
It occurred early on December 29 near the town of Nis in central Serbia, on a highway that links Bulgaria and Greece to northern and western Europe.
The car hit a protective barrier on the highway, police said in a statement.
State TV cited doctors at an emergency hospital in Nis as saying that many of the injuries were grave and that one victim had to have both legs amputated.
The patients have "extremely severe head and limb injuries. ... We are doing everything we can to save their lives," doctor Miodrag Lazic told state boadcaster RTS.
Thousands of migrants are stranded in Serbia looking for ways to reach wealthier Western European countries, which have sought to curb the influx.