Police said on Monday they had arrested 42 people for an illegal strike at the Rasimone mine, a joint venture between Royal Bafokeng Platinum and Anglo American Platinum.
About 1,500 people embarked on the illegal strike and police were called in to monitor the situation, the South African Police Service said in a statement.
The mine is located near Rustenburg, about 120 km northwest of Johannesburg, an area that has been hit by five weeks of labour unrest.
