Some supporters at the ceremony today chanted the name of President Jacob Zuma, who has fended off challenges to his leadership from within the ruling African National Congress party.
The party is under strain because of national discontent over Zuma's dismissal of a respected finance minister last month and past scandals linked to the president. On Friday, tens of thousands of South Africans protested against Zuma across the country.
The memorial near Johannesburg was held in honor of Chris Hani, who was fatally shot on April 10, 1993. A year later, white minority rule ended with South Africa's first all-race elections.