A leader for 12,000 strikers at Anglo American Platinum operations outside Johannesburg says they will not return to work until their wage demands are met.

Evans Ramokga said Tuesday that the miners were "unhappy" with Amplats' offer to reinstate the fired miners and give them a once-off hardship allowance of 2,000 rand (about $230).

Police spokesman Dennis Adriao said a power station on Amplats' property in Rustenburg had been set alight by unknown people on Tuesday morning. Adriao said police later had to fire rubber bullets and stun grenades to disperse a large group of strikers there.

But Ramokga denied the miners were committing acts of violence, saying only that they continue to withdraw their labor. The miners are demanding 16,000 rand ($1,800) in monthly pay.

Amplats is the world's top producer of platinum.