The Sharpeville massacre occurred on 21 March 1960, when police opened fire on a crowd of people who had assembled outside the police station in the township of Sharpeville in the then Transvaal Province of the then Union of South Africa (today part of Gauteng) to protest against the apartheid system and its pass laws. A crowd of approximately 5,000 people gathered in Sharpeville that day in response to the call made by the Pan-Africanist Congress to leave their pass-books at home and to demand that the police arrest them for contravening the pass laws. The protesters were told that they would be addressed by a government official and they waited outside the police station as more police officers arrived, including senior members of the Security Branch.