Nineteen schoolchildren and one adult have been killed after the minibus they were travelling in crashed into a lorry and exploded into a ball of fire.
Many of the children were thought to be trapped in the bus after it crashed in Mpumalanga province, north of the city of Pretoria, in the north-east of the country.
Images posted by ER24 medical service on Twitter show the twisted and mangled minibus on its side.
Around 13 children were found trapped inside the vehicle as the flames were put out.
The collision occurred between the communities of Verena and Bronkhorstpruit, some 45 miles from Pretoria.
Russel Meiring, spokesman for the ER24 emergency medical service, said: "Paramedics arrived on the scene to find the fire services already in attendance. The fire services had already extinguished the burning vehicle, which was found lying on its side."
Several other children were injured, with reports that some were dragged from the wreckage by people at the scene.
In a statement, ER24 said: "The children were treated for their injuries and provided with advanced life support interventions before they were transported to various hospitals in the area for further treatment".
The cause of the incident was not immediately known.