The world's top platinum producer Anglo American Platinum has started disciplinary procedures that could see thousands of its striking workers in South Africa sacked.
"We have been left with no choice but to initiate disciplinary action, which could lead to dismissals," Amplats chief executive officer Chris Griffith said.
The company said attendance remained below 20 per cent at its Rustenburg mines despite repeated calls urging employees to end a two-week wildcat strike, with several deadlines for strikers to return to work pushed back.
An appeal for an immediate return was issued on Wednesday with a warning that workers would face disciplinary action and risk being fired, with 20,000 ounces of platinum lost since September 12.
But striking workers on Thursday appeared unfazed by the threats of dismissal.
"We are not worried about that," one worker said outside Thembelani, one of the five Amplats mines sitting on South Africa's platinum belt. "We want money, we want money."
Another miner, who asked not to be identified, also dismissed the company's warning as empty.
"The company will not fire us. They said at (the Lonmin mine in) Marikana they would fire those guys, but now they're not firing," he said shortly before Amplats announced it had started acting against strikers.
Amplats accounts for 38 per cent of global platinum production, providing a resource that is key in vehicles and jewellery. It is the subsidiary of the country's largest private sector employer, Anglo American.
Workers are pushing for at least the 11-22 per cent raises that Lonmin miners at the nearby Marikana mine received after a deadly strike that left 46 dead, 35 of whom were killed by police.
There have been fears the Lonmin deal set a dangerous precedent, as the workers secured the deal by bypassing recognised union structures.