What event occurred in Pretoria on 9 August 1956 that caused a riot?

On 9 August 1956, thousands of women marched to the Union Buildings in Pretoria to protest against apartheid-era pass laws in South Africa, which required black individuals to carry passbooks. The protest was part of the larger Women's March organized by the Federation of South African Women. While the event itself was peaceful, tensions escalated as police attempted to disperse the crowd, leading to confrontations and unrest, ultimately highlighting the women's resistance against oppressive laws.