Julius Malema told a crowd at the Marikana platinum mine they should continue their wildcat strike until their pay is doubled and also called for the nationalization of South Africa's mining industry.
Police opened fire on a rowdy demonstration by strikers Thursday at the mine owned by Lonmin PLC. The shooting left 34 people dead.
"Miners around the country should stand in solidarity with the miners at Lonmin," said Malema, who was expelled from the African National Congress this spring. Malema earlier called for President Jacob Zuma to resign over the massacre.
CNN said Zuma and the ANC have been accused by the miners union of being too cozy with South Africa's mining companies. Political analysts have said Malema's solidarity with the miners appeared to be part of his overall strategy to discredit Zuma.