The government sounded the alarm on the economic fallout of the turmoil as leading platinum producer Aquarius Platinum and top ferrochrome company Xstrata Alloys each closed mines in the strife-hit Rustenburg region.
"Our government will not tolerate these acts any further," Justice Minister Jeff Radebe told journalists.
The clampdown will target illegal gatherings and the carrying of weapons as thousands of miners, many armed with spears and machetes, mobilise at shuttered mines with fiery threats of violence and of further strike action.
The move was the government's boldest since police shot dead 34 protesters last month at Lonmin's crippled platinum mine.
Officers used stun grenades to disperse 1,500 protesters at Aquarius and arrested seven people shortly after the announcement.
The unrest has snowballed with workers downing tools at other mines since Lonmin's strike exploded into bloodshed.
The world's number one platinum producer, Anglo American Platinum (Amplats), and the number three company, Lonmin, have already ground to a halt in the mineral-rich region.
"This is not a state of emergency. We want to bring back public order in those affected areas so that the economy of our country can continue to run normally," said Radebe, who warned police would make arrests.
"So all those who are involved in illegal activities are going to be dealt with very swiftly without any further delay," he said.
The mining sector, the backbone of South Africa's economy, directly employs around 500,000 people and accounts for nearly one fifth of gross domestic product when related activities are included.
It also brings in about half of the nation's export earnings.
The labour strife has also spread to the gold sector where 15,000 Gold Fields miners have been striking since Sunday.
The world's leading ferrochrome producer, Xstrata Alloys, and the fourth largest platinum producer, Aquarius, said the growing protests and tensions in the area had forced the temporary halt of operations.
Finance Minister Pravin Gordhan warned that the unrest, if unchecked, would hit already slowing economic growth and raise joblessness, while the violence would damage investor confidence.
"If this instability continues and the lack of production continues, firstly the cost will be in terms of the overall growth numbers in South Africa," he told reporters.
Hopes were dashed Friday of a breakthrough at Lonmin -- which has warned that an indefinite strike will put 40,000 jobs at risk -- when workers rejected a wage offer by the London-listed firm as "an insult".
"The workers rejected the offer," representative Molisi Phele told AFP of the 986 rand ($120; 92 euros) pay increase put forward by the company.
The proposal was the first since the strike paralysed its Marikana operations, where a total of 45 people have been killed since last month.
At the end of a fresh round of talks on Friday, Lonmin had doubled its initial wage offer for rock drill operators, the group that led the strike, SAPA news agency said.
Worker turnout plunged to 0.31 percent on Friday, a record low since workers walked off the job on August 10.
Welcoming the state's efforts to restore calm, Lonmin said mediated talks will resume on Monday.
"Lonmin has re-affirmed the offer on the table. Disappointingly there has been no real movement on the worker demands and the worker delegates have gone back to consult with their constituents," it said.
The industrial unrest has become a political battleground, with Julius Malema, the firebrand former African National Congress youth leader, using the unrest to attack President Jacob Zuma whose ruling ANC expelled him for ill-discipline.
"Illegal gatherings, the carrying of dangerous weapons, incitement as well as threats of violence against anyone in the affected areas will be dealt with accordingly," warned Radebe.
Cynthia Carroll, chief executive of Anglo American, also welcomed the government's comments after the firm closed five mines this week.
"The platinum industry provides employment to hundreds of thousands of South Africans and makes a critical contribution to the South African economy," she said in a statement.
Amplats employs 24,000 people in Rustenburg.
"We must secure its future economic viability and the livelihoods of its employees."
