All were declared dead on the scene; eight injured passengers were taken to a local hospital. The road was closed.
A trailer being towed by a minibus and a truck collided on the N1 between Leeu-Gamka and Prince Albert Road at about 1am on November 15, 2011, Captain Malcolm Pojie said. The minibus overturned when it was rammed from behind by another minibus.
Pojie said: "The main cause of the accident is not clear. Police are still working on the scene. It seems all the people killed were in the minibuses."
A culpable homicide docket has been opened.