There has been a serious accident involving several heavy motor vehicles and at least one light motor vehicle on the N2 in Hluhluwe, about 40km from Lake St Lucia, in KwaZulu-Natal.
All vehicles, including a tanker, are currently alight and the flames have spread to the nearby bush.
Emergency services workers and firefighters are currently on the scene, says KwaZulu-Natal emergency services spokesperson Robert McKenzie.
"Firefighters are trying to contain the blaze which is burning out of control. It has also set the adjacent bush alight," he says.
The number of casualties is unknown at this stage.
The cause of the accident is also unknown.
"We'd like to advise motorists to not approach the scene as there is still a large fire burning," McKenzie adds.