An underground strike at Anglo American Platinum's (Amplats) Tumela Mine in Amandelbult, Limpopo, continued on Thursday, the company said.
The sit-in by about 169 employees was still on, said spokesperson Mpumi Sithole.
"The night-shift on Wednesday and morning-shift today [Thursday] reported for duty and proceeded underground to carry out normal work duties," she said.
The workers were demanding to see managers to discuss their grievances.
Sithole said mine management was talking to trade unions to resolve the sit-in, and encouraged employees to continue using the existing channels to address any labour issue.
Management was still trying to determine the workers' exact demands.
"The safety of all our employees is of vital importance to us; therefore we advise against any sit-in which may lead to an unsafe work environment, and encourage employees to abide by the spirit of peace and stability framework adopted by all stakeholders," she said.
Association of Mineworkers and Construction Union (Amcu) secretary Jeff Mphahlele said the strike was apparently related to bonuses.
"It is not clear whether they [workers] are our members. We have sent people there and are waiting for a report."
Another strike, about retrenchments, was looming at Amplats's Rustenburg operations.
The workers' committee, which led a strike in September, said the strike would start on Friday.
"The committee will meet today [Thursday] to discuss the issue and there is a strong possibility that the night-shift will not go underground," said committee member Evans Ramokga.
He said the company was not backing down on retrenchments, and workers had taken it upon themselves to fight.
"Unions have done their part and negotiated on our behalves. Now the workers have decided to lead their cause. No one is happy about the retrenchments."
He said after mass meetings at different shafts, workers decided to go on strike.
"Workers are saying if Amplats cannot run the mines they must leave and surrender the mines to another company that will save jobs."
Sithole said management was aware of the issues which had been raised by employees through the media.
"We encourage our employees to utilise the existing channels in place to address any labour issues and advise against illegal work stoppages, as these may lead to disciplinary action," she said.
North West legislature speaker Supra Mahumapelo appealed for calm in the province's platinum belt.
"The speaker noted the pending retrenchments with great concern, and thus calls upon all stakeholders to handle this matter responsibly so that we do not go through another... regrettable incident," said his spokesperson Mongezi Tsenca.
In August, 44 people died in strike-related unrest at Marikana. Thirty-four of them were shot dead by police. The other 10 -- including two policemen and two security guards -- died the week before.