Northam halts ops at Zondereinde after accident

The company said investigations into the cause of the accident, a "fall of ground", had been launched, but that it was not immediately clear how much platinum output would be lost.

"For the moment production is suspended and there are a number of issues that need to be done before (the suspension) can be lifted. We don't know how much will be lost," spokesperson Marion Brower said.

The National Union of Mineworkers (NUM) said the accident had taken total mine deaths this year to 70, calling into question mining companies' assertions that safety is a top priority and is constantly being improved.

"It is shocking that the 70 that died is what the Chamber of Mines calls 'safety progress'," Peter Bailey, the NUM's chairperson for Health and Safety, said.

South Africa has a dire mining safety record compared with the industrialised world, partly because it has some of the deepest mines. Last year, 165 miners died in South African mines.