CAPE TOWN, Jan. 6 (Xinhua) -- A minibus taxi overturned on a highway in Western Cape Province of South Africa, killing nine on Friday, said authorities.

Six people died on the scene in Karoo while three others died later in hospital, said the Western Cape Traffic Department.

Several other passengers were injured and taken to hospital for treatment, according to the department.

A preliminary investigation has found that the driver of the taxi apparently lost control of the vehicle due to fatigue or driving under the influence of alcohol.

It is unclear whether the driver was among the dead.

The accident took place despite the "Drive Safely Campaign" during the festive season.

To ensure road safety, traffic authorities across the country have pulled over and checked almost a million vehicles and tested over 100,000 drivers for drunk driving since the Christmas and New Year holidays in December, according to the Road Traffic Management Corporation (RTMC).

As the festive season came to an end, traffic law enforcement authorities stepped up efforts to deal with increasing traffic volumes on the roads.

Road carnage is a daily phenomenon, particularly during holidays in South Africa.

More than 10,000 people have died in traffic accidents during the previous festive season in South Africa, while no official figures have been released for this year so far.