25 years to the day after the infamous Sharpeville Massacre, in which 69 people were killed, the South African Police opened fire on a crowd of people in Langa, Uitenhage, in the Eastern Cape. At least 20 people are reported to have been killed in what has become known as the Langa or Uitenhage Massacre. Some reports register the death tally at 28. They were on their way to attend a funeral when the police gunned them down. Although the massacre is not as widely remembered today as other apartheid atrocities, such as those at Sharpeville and Soweto, it produced a tangible shift in the political situation at the time. It provoked renewed school boycotts and resulted in further clashes between communities and the police throughout the country. By July the tensions had grown leading the apartheid government to declare a state of emergency in 36 magisterial districts around the country - including the Uitenhage/Port Elizabeth area in the Eastern Cape. The following year saw the state of emergency extended to include the entire country.
References

Robert J. Thornton. “The shooting at Uitenhage, South Africa, 1985: the context and interpretation of violence”, American Ethnologist 17(2), (1990).|Nigel Worden. The making of modern South Africa: conquest, segregation and apartheid. Juta & Co. Ltd. South Africa (1994)