Overnight workers at Anglo American Platinum's Rustenburg operations refused to go underground to protest company plans to close mines.
"They didn't go underground," Evans Ramogka, a labour leader and activist at an Amplats mine in Rustenburg, said on Wednesday.
A company spokesperson said she could not immediately comment because she was waiting for an operational update from managers at the mines.
Local media reported workers would be meeting later to plot wider strike action after Amplats, a unit of global mining group Anglo American, unveiled plans on Tuesday to mothball two South African mines, sell another and cut 14 000 jobs.
Amplats, the world's number one platinum producer, said the initiatives were needed to restore profits.
But the company also risks provoking a repeat of last year's violent wildcat strikes that left over 50 people dead.
Amplats said on Monday it would likely fall to a full-year loss because of last year's costly strikes.
Meanwhile, Mineral Resources Minister Susan Shabangu said on Tuesday the retrenchment plans by the company came as a shock to the government.
"It is regrettable that the company consulted with [my] department less than seven days ago, despite the major socioeconomic ramifications of its decision," she told reporters in Pretoria on Tuesday. "We are surprised and shocked ... "
The mining giant announced the possible job cuts earlier in the day, saying this would form part of a major restructuring at its strike-hit South African operations.
The firm would close four shafts and sell a mine considered unsustainable, it said.
"As a result of the proposed changes to the business, a total of up to 14 000 jobs may be affected – 13 000 of which will be in the Rustenburg area."
Anglo's 'change of leadership'
Shabangu said Anglo American approached her department last year to say it was facing problems and considering restructuring. She said the company was told to discuss any such plans with the department first.
Yet, the company waited until seven days ago to do so. Shabangu asked if this was a sign of new company management.
"When the horse has bolted, then they come to us."
She was referring to Mark Cutifani, who would replace outgoing chief executive Cynthia Carroll in April.
The minister said the company's mining rights were renewed in 2010 for 30 years, on condition the mining programme was uninterrupted and operated at maximum capacity.
"Anglo American Platinum imposed large-scale retrenchments in 2009, and [Monday's] announcement seems to present a pattern of unsustainable business decisions linked to change of leadership in the company," Shabangu added.
Effects of retrenchment
She said it was clear to the department this decision lacked vision and long-term business planning.
"In our analysis Anglo American omitted to invest in the future sustainable development of the mine."
The minister said her department regretted the company's conduct in making such an important business decision that would affect the country's economy.
She said miners and their families would be severely affected by such retrenchments as there was little work in and around Rustenburg.
"It tends to create a grim future for those workers," Shabangu said.
The company's plans to move fired workers to other industries, such as bricklaying, were not sustainable.
"You can't train at the tail end of everything ... those skills are not created in a sustainable way. They must not talk about sectors they do not understand."
The department would review whether the entire Anglo American portfolio complied with existing legislation. – Reuters, Sapa