Members of South Africa's National Union of Mineworkers (NUM) will decide on Wednesday if they will return to work at Northam Platinum's Zondereinde mine, which was shut on Monday after violent clashes between NUM and a rival union.
Northam made the initial decision to close operations at the mine but on Tuesday asked the workers to return, saying calm had been restored.
But NUM, the majority union at the mine, and arch rival the Association of Mineworkers and Construction Union (AMCU) have both said their members will not go back until they feel it is safe to do so.
NUM spokesman Livhuwani Mammburu said the union's members would hold a mass meeting at midday to decide if they would go back underground.
"It is up to the members to decide," he said.
AMCU officials could not immediately be reached for comment.
A Northam spokeswoman confirmed the mine remained closed for a third day.
Monday's flare-up was sparked by the murder of an NUM member and Northam employee on Sunday. Another miner, whom AMCU said was affiliated to it, was fatally stabbed in Monday's scuffle.
NUM says that Sunday's killing brings to six the number of its members who have been murdered, including five last year.
The clashes have heightened concern over a potential repeat of periodic outbreaks of union violence that have resulted in deaths and operational stoppages across the sector.
The Zondereinde mine produces about 300,000 ounces of platinum a year, according to Northam's website, and accounts for about 70 percent of the mid-tier producer's revenue.