More than 2,000 miners at Implats' Platinum mine near Rustenburg in the North West remained underground on Monday afternoon after an illegal protest started at two shafts earlier in the day.
Criminal and internal disciplinary investigations are under way after the illegal underground sit-in protest at Gold One mine in Springs on the East Rand in Gauteng.
AMCU supporters are accused of trying to force the mine to reinstate 74 workers, axed in October for staging an illegal strike, by blockading the mine shaft, trapping almost 500 workers underground in a protracted labour dispute.
More than 400 gold miners who remained underground for four days, amid tensions between unions and the mine owners, returned to the surface on Monday, some telling AFP that workers had collapsed due to lack of food.
Three mine workers managed to escape and two were released due to their medical conditions after being stuck in an illegal underground sit-in at Gold One mine in Springs, on the East Rand.