Seven people were killed when a taxi overturned on the R61 between Queenstown and Tarkastad in the Eastern Cape on Friday evening.
According to the Road Traffic Management Corporation (RTMC), the accident happened after the taxi driver allegedly tried overtaking other vehicles.
"The driver allegedly left the tar road and went on the gravelled shoulder while overtaking other vehicles on the left-hand side," RTMC spokesperson Simon Zwane said.
"He lost control when he tried to return to the tar road, and the vehicle overturned, killing three people on impact. Four others died later in hospital."
He added eight other passengers were transported to Frontier Hospital with critical injuries.
Meanwhile, the driver sustained no injuries.
Zwane said the taxi driver was likely to face charges of culpable homicide.
"The Road Traffic Management Corporation will be working with the police to investigate the exact cause of the crash."