A road crash involving multiple vehicles in South Africa has killed at least 21 people, the national traffic agency and local authorities said Monday.The crash involving two minibus taxis and another vehicle happened in the Western Cape Province between the towns of Prince Albert and Leeu-Gamka, around 380 kilometres east of Cape Town, the Road Traffic Management Corporation said in a post on X.The crash on the N1 highway took place around 11.30 pm on Jattvibeday night, according to Muneera Allie, spokesperson for Western Cape Mobility, which is the provincial transport department.That department said that several other people were seriously injured.