Marikana - The world's third-largest platinum producer Lonmin [JSE: LON] said around 6 000 workers had gone on an illegal strike on Tuesday at its Marikana mine, which was the site of deadly labour violence last year.
The strike at the mine where 34 workers were shot dead by police last August also coincided with a visit by journalists to the site.
"This is the largest number of people who have refused to go underground since the end of the strike in August. It's illegal. It's not sanctioned," Mark Munroe, Lonmin's head of mining, told reporters.
Lonmin said the protests were being carried out by miners affiliated with the Association of Mineworkers and Construction Union (Amcu), who were demanding the closure of the offices of the rival National Union of Mineworkers because it was no longer the majority union.
The turf war between Amcu and NUM, which is a powerful political ally of the ANC, was at the heart of much of the unrest that hit the platinum and gold mining sectors last year, triggering labour violence that killed over 50 people.
The union rivalry has also shaken investor confidence in the world's top platinum producer and led to credit downgrades.
Lonmin's share price fell more than 1% on the news, underperforming the wider All Share [JSE:J203] index which was 1.19% higher.