The powerful South African mining union NUM called for an indefinite strike starting Sunday at the nickel mine in eastern Nkomati over demands for bonus pay.

The action is set to begin at 7:00 pm (1700 GMT) and "will continue indefinitely until the NUM demands are complied with," the deputy general secretary of the union and chief negotiator William Makgabo Mabapa said in a statement Saturday.

The strikers are demanding a bonus of 3,000 rand (210 euros, $230) for employees who have worked five years and 6,000 rand for those who have worked 10 years, it said.

So far the mine jointly owned by the Russian group Norilsk and South Africas's African Rainbow Minierals (ARM) has offered bonuses of 3,000 rand to those with 10 years of service.

Contacted by AFP, ARM said only that it had been advised of the planned strike.

ARM, whose founder and CEO Patrice Motsepe is considered South Africa's richest black man, owns a 50-percent stake in the mine, while Norilsk owns the other half.

Sunday marks the third anniversary of the Marikana massacre of 34 striking platinum miners by police, the worst violence involving the security forces since the end of apartheid in 1994.

South Africa, the world's top platinum producer and seventh gold producer, is less known for its nickel, supplying only two percent of world output.

The Marikana miners demanding better wages and living conditions were gunned down on August 16, 2012, after the police were deployed to break up a wildcat strike that had turned violent.

Ten others were killed in the days preceding the incident, including two police officers and four non-striking workers.

No official commemoration is planned, but the Marikana anniversary will be marked by around 50 events across the country.