There were 49 miners on the rota at the time of the accident, according to state television RTS, for which the cause is still unknown.
At least eight miners have been killed and about 20 injured when a shaft collapsed in a state-owned coal mine in southern Serbia, RTS state television has reported.
The accident in the Soko coal mine happened around 5am local (0300 GMT) on Friday.
Rescuers were trying to determine how many miners were trapped in the shaft, the broadcaster said, quoting health authorities in the southern town of Aleksinac, 200 kilometres from Belgrade.
Goran Vidic, head of the local hospital, was quoted as saying that all non-essential surgery had been cancelled and some patients had been discharged to make room for casualties.
"The situation here is difficult, relatives are here, people are upset," Vidic said.
There were 49 miners on the rota at the time of the accident, most of them from Aleksinac, RTS said.
The Aleksinac coal mine is prone to methane saturation and in November 1989 some 90 miners died in an explosion there.