At least 21 people were killed and four others seriously injured in a multi-vehicle crash in South Africa’s Western Cape province on Sunday night, authorities said Monday.The crash involved two minibus taxis and an SUV on the N1 highway between the towns of Prince Albert and Leeu-Gamka, around 380 kilometres east of Cape Town, the Road Traffic Management Corporation said.According to the Western Cape Mobility department, the accident began when the two minibus taxis collided head-on. The SUV then crashed into the wreckage.The crash occurred at around 11.30pm, said Muneera Allie, spokesperson for Western Cape Mobility. Three victims were taken to a hospital but were declared dead on arrival, police said.The traffic agency warned that the death toll “may change as emergency services and authorities in the Western Cape continue their assessment of the scene.”Minibus taxis are the main mode of public transport for millions of people in South Africa and are frequently involved in fatal road accidents, the Associated Press reported.Two separate minibus taxi crashes in January killed at least 25 people, including 14 children.