Polokwane - Forty-five patients at Letaba hospital, east of Limpopo, were evacuated on Monday after the psychiatric ward caught fire, the provincial health department said.
The cause of the fire was unclear. No deaths or injuries were reported, spokesman Macks Lesufi said.
The patients were transferred to three other hospitals in the area.
The fire began around 4.50pm, Lesufi said. Patients were evacuated by 7pm.
Police spokeswoman Colonel Ronel Otto said a forensic team would investigate the cause of the fire on Tuesday morning.
Sapa