The world's top platinum producer Anglo American shut down its main South African operations Wednesday as fears rose that widening strikes are spiralling into an industry revolt.
The latest unrest broke out on roads leading to Anglo American which halted work at its Rustenburg mines in the same region as the London-listed Lonmin plant where 45 people have died in a wildcat strike that started last month.
"We have taken this decision to suspend our operations in order to help ensure the safety of our employees -- our absolute priority," said Cynthia Carroll, chairperson of Anglo American Platinum (Amplats).
"Our people want to work and it is unacceptable that they are not able to go to work safely and instead are facing considerable intimidation."
South Africa's key mining sector, which contributes around a fifth of the country's GDP, has been hit by a wave of increasingly militant strikes that have spilled from the world's richest platinum mines into the gold sector.
Security guards on Wednesday fired teargas to disperse hundreds of striking Gold Fields miners who tried to block a goods train with cement blocks and iron bars at a shaft near Johannesburg where 15,000 have downed tools since Sunday.
Anglo American denied its workers were on strike, saying staff were unable to report for duty and were being intimidated with the threat of violence.
Police said workers had converged along roads to mine shafts, barricading them with rocks and tree trunks to prevent anyone from reporting for duty.
Around 1,500 workers, some waving sticks and machetes, marched to the mine's smelter and demanded a shutdown in operations.
Tensions have been inflamed by maverick former youth leader Julius Malema who has been visiting strife-hit mines and calling for operations to be made ungovernable and for widespread strike action.
"We are calling for mining change in South Africa. We want the mines nationalised," he told Radio Talk Radio 702.
"Now we want to show them that we mean business. We are going to be engaging in very peaceful yet radical and militant action that will hit straight into the pockets of white monopoly capital."
At least 45 people have died -- including 34 in a police shooting last month which has been described as the worst case of police violence since the end of apartheid -- at the Marikana mine, just 20 kilometres from Amplats.
The site is run by Lonmin, the world's third biggest platinum producer, and workers there have yet to reach a deal with management and return to work.
Some unions and Malema have since whipped up Lonmin workers' demand for a basic salary of 12,500 rands ($1,500) -- a threefold increase on the industry average -- into the centrepiece of a national campaign.
Some Amplats workers are eyeing even more.
"We want 14,500 (rand), but we can't settle for less than 12,500," Aggripa Phiri, a 40-year-old team supervisor told AFP, rebuffing Amplats claims that workers on the streets were not its employees.
"See our clock cards," he said as the group of protesters flashed their bright blue employee cards.
Police armoured vehicles guarded the smelter entrance from the outside, while mine security kept watch just inside the gate with their armoured trucks.
Gaddhafi Mdoda, 32, Amplats miner representative, said workers were willing to discuss wages with the mine's management.
"This is what I'm looking forward to do, to negotiate. Because we are not looking for the fight. We have seen our brothers die in the massacre in Marikana. That's one of the things we don't need to see right now."
The strikes have been used as a battleground for a leadership struggle ahead of a key ANC election in December.
Malema, who was expelled from the ANC earlier this year, has used the miners' discontent to launch fresh attacks on President Jacob Zuma and his leadership who have sought to assure investors of stability for foreign investors.
The government has vigorously condemned what it describes as irresponsible rabble-rousing but Malema has struck a chord with many who see the mining giants as the symbol of the social inequalities plaguing the country.