Six children, aged eight to 13, and an adult died when their bakkie overturned near Underberg, in KwaZulu-Natal, on Tuesday afternoon, paramedics said.
Another 13 children were injured, six of them critically, in the accident on the R617, ER24 spokesman Derrick Banks said.
"When emergency personnel arrived on the scene, they found a bakkie had rolled numerous times, with patients strewn across the embankment."
KwaZulu-Natal transport and community safety spokesman Kwanele Ncalane said the bakkie was carrying pupils from the Donnybrook and Blessed Luanda primary schools to Underberg when the driver lost control of the vehicle.
"According to eyewitnesses the driver was trying to overtake in a sharp bend. The driver also died on the scene," Ncalane said.
Banks said several children had been taken to a nearby clinic by the time paramedics arrived. The injured children were stabilised and taken to hospitals in Pietermaritzburg and the surrounding area.
Transport and community safety MEC Willies Mchunu offered his condolences and lamented the loss of the children.
"This once again confirms that road accidents are depriving us of the future generation of young people who can take this country forward. It is heart-breaking to lose such young people in a road accident."