Six people were killed and three others injured during a head-on collision on the N12 highway, roughly 15km outside of Potchefstroom, paramedics said on Thursday.
Paramedics and other emergency service officials arrived at the accident scene just before midnight on Wednesday and found a bakkie and a second vehicle, both of which were significantly damaged, obstructing the road, ER24 spokesperson Russel Meiring said in a statement.
Three people were found inside the bakkie and six inside the second vehicle.
"Paramedics assessed the patients in the [second vehicle] ...and found that two men, a woman and two children, aged between three and four, had all sustained numerous injuries and showed no signs of life," said Meiring.
"They were declared dead at the scene as nothing could be done for them."
Of the three men paramedics found inside the bakkie, two sustained moderate injuries while the third was later declared dead at the scene.
Paramedics provided advanced life support intervention to a woman, the sixth patient in the second vehicle, who was found in a critical condition.
She was airlifted by a private medical helicopter to Lenmed Randfontein for urgent treatment. The remaining two injured patients were transported by ambulance to the nearest hospital, Meiring said.
The exact details surrounding the incident are not yet known.