Johannesburg - Glencore Xstrata said on Thursday three of its chrome mines in South Africa were at a standstill after up to 1 500 workers embarked on an illegal strike this week.
The dispute at the mines near Steelpoort, northeast of Johannesburg in the Limpopo province, adds to long-running friction in the mining industry that has caused production to slow, raised concerns about the economy and sent the rand to new four-year lows.
"The strike started on Tuesday and all three mines are not in operation," said Glencore Xstrata chrome spokesperson Christopher Tsatsawane.
"We have dismissed 200 employees at Helena mine after they failed to return to work after three ultimatums."
He said more employees could be dismissed. Final ultimatums were yet to be issued to strikers at its Magareng and Thorncliffe mines.
Tsatsawane said the workers, most of whom belong to the Association of Mineworkers and Construction Union (Amcu), had stopped work in solidarity with an individual who claims he was assaulted by a shift supervisor.
Dismissal of workers is not likely to go down well with trade unions, already embroiled in a turf war and on the brink of biennial wage negotiations.
South Africa, home to around 75% of the world's chromite reserves, has become a flashpoint of violent labour strife as Amcu and the dominant National Union of Mineworkers (NUM) battle for members.