The world's top platinum miner ordered 26,000 striking workers in South Africa to report for disciplinary hearings Tuesday or risk the sack, as gold giant AngloGold Ashanti warned strikers there they might be forced to scale down their operations.
Anglo American Platinum (Amplats) told its striking workers they had to turn up in person to explain their absence from work or face dismissal.
"The company will also be left with no alternative but to dismiss, in their absence, all employees who do not present themselves," it said in a statement.
At AngloGold Ashanti meanwhile, the chief executive of the world's number-three gold producer warned that their patience was wearing thin after more than a week of illegal strikes over pay.
"Clearly for South Africa's gold sector, as for many others, there is a very clear trade-off between investing in the sustainability of our business and employment," Mark Cutifani said in a statement.
"If the current unprotected strike continues, it compounds risks of a premature downsizing of AngloGold Ashanti's South African operations," said Cutifani.
Around 24,000 AngloAshanti Gold workers have downed tools at its South African operations.
Any closures would hit its operations that are "marginal or were struggling to maintain a viable margin," Cutifani warned at a news conference.
"Where downsizing and closures occur we are unlikely to return to these shafts in the short- to medium-term due to the associated recovery costs.
"We certainly hope it doesn't get to that but clearly if we have to do something, we will. We have to protect the long-term viability of the business," said Cutifani.
The mining industry in South Africa was teetering on the brink, with the platinum sector under severe stress, he warned.
"The industry is on a knife's age, 50 percent of the platinum industry is losing cash now, before you consider additional salary increases. It's very serious."
All gold production has been halted at AngloGold Ashanti's operations in South Africa due to the strike, which started last month. The world's number three gold producer is losing up to 32,000 ounces of the precious metal each week.
Around a third of AngloGold Ashanti's output comes from South Africa.
South Africa's mining industry is buckling under a wave of strikes that have sucked in around 80,000 workers, according to experts in the vital industry.
Late on Monday, global ratings agency Moody's downgraded the unsecured credit rating of GoldFields, the world's 4th gold producer, from positive to stable.
Its KDC West mine, which employs 15,000 people near Johannesburg, has been crippled by a strike since September 9.
GoldField's downgrade "reflects a combination of the weakening of the South African government's credit profile and also the continued growing labour unrest in the company's South African mines, which is likely to lead to higher-than-expected wage demands from miners," said Moody's.
The agency last week dropped South Africa to a Baa1 rating, a move likely to further alarm investors already worried by the strikes and political instability.
South Africa's mining sector has been rocked by protests since a deadly wildcat strike that began in August at the world's number three platinum producer Lonmin and spread to other mines.
Lonmin workers last month sealed a hefty wage hike, ending a six-week strike that claimed 46 lives.
An inquiry opened Monday into the police killing of 34 miners at Lonmin and related violence, in what was the country's worst bloodbath since the end of apartheid.