World No. 1 platinum producer Anglo American Platinum (Amplats) said on Friday 100 workers had refused to go underground at its Thembelani mine in South Africa, a sign that simmering discontent in the sector has not been contained.There was no immediate threat to production at Amplats as the mine employs over 4,100 people, but the sector is on tenterhooks in the wake of a violent strike at Lonmin that saw 34 striking miners gunned down by police last week.Amplats said in a statement that 6 workers were having talks with management regarding wage demands."The rest of the employees have proceeded underground and the situation is calm,” the company said. Smaller producer Royal Bafokeng Platinum said it had received an undertaking that the 500 employees who participated in an illegal strike earlier this week would return.It said allegations of intimidation would be independently investigated and appropriate action would be taken if required."In spite of the loss of approximately 14,000 tonnes planned to have been hoisted over the three days ... total tonnes milled for the month should remain unaffected due to the stockpile processed during this period,” it said.In the fortnight since the Lonmin strike began the spot price of the white metal used for emissions-capping catalytic converters in cars has spiked over 10 percent.Already struggling with soaring costs and weak global demand, the platinum sector has been hit by a union turf war, transforming workers into warriors as the Association of Mineworkers and Construction Union takes on the dominant National Union of Mineworkers.South Africa sits on about 80 percent of the world’s known platinum reserves.