The accident involving a Toyota Quantum minibus taxi and a Toyota Hilux double-cab bakkie reportedly occurred on the N2 near Dutywa in the Eastern Cape province, and police have opened a case of culpable homicide.
According to local media reports, nine of the deceased were in the minibus taxi, including the driver, four male and four female passengers, and the other three were male passengers in the double cab bakkie.
Authorities said three other people were injured in the accident, which occurred Saturday night.
More than 80 people have died on Eastern Cape roads since the start of the festive season, the broadcaster reported.