A wildcat strike at Sibanye Gold's Cooke operations west of Johannesburg continued on Sunday and 138 illegal miners there have been arrested since the stoppage began Tuesday, a company spokesman said.
Sibanye said the strike, which has seen 16 miners assaulted in a wave of intimidation, was triggered by worker anger at a company drive to root out illegal miners, which has included the arrest of employees for collusion and a policy that forbids food in underground operations.
Illegal gold mining has plagued South Africa for decades, with bullion pilfered from both operating and disused mines.
Sibanye has vowed it will clear all illegal miners from its shafts by January 2018.
The Cooke mines have been at the center of illicit activities at Sibanye's operations. Prior to the walkout, 101 illegal miners had been arrested this year along with 58 employees accused of collusion.
Illegal miners can spend weeks underground, which requires large amounts of food and water — which is why Sibanye has banned its employees from taking any food underground, with union agreement.
It is also why so many illegal miners have been forced to the surface since the strike began, as their source of food and water — colluding employees — has dried up, one of the inadvertent consequences of the stoppage.
The Cooke operations, which employ almost 4,000 underground miners, are marginal and Sibanye spokesman James Wellsted said their viability is at risk if the strike becomes prolonged.
"One of the reasons why the mine has not been performing is because many of the employees have been focused on assisting illegal miners instead of their jobs," he said.