Up to 4,000 mineworkers staged a sit-in strike at an Anglo American Platinum mine in South Africa's restive platinum belt Friday over the suspension of four leaders, a union representative told AFP.
Workers from the upstart Association of Mineworkers and Construction Union (AMCU) at the mine's Thembelani shaft in Rustenburg have refused to come out since the 4 am (0200 GMT) shift started, according to George Tyobeka, an AMCU leader.
"They don't want to come out from underground because they want their leadership's suspension lifted," said Tyobeka.
Around 3,000 to 4,000 people were striking, he said.
Anglo American Platinum confirmed the industrial action, but said around "2,400 employees" were underground and were "being prevented from exiting underground by a group of employees."
It confirmed the action had been ignited by the suspension of four local unionists "for inappropriate behaviour which is against our behavioural procedure."
The four AMCU leaders had been suspended amid allegations they submitted fraudulent membership applications in a bid to inflate union membership numbers.
AMCU and rival union the National Union of Mineworkers (NUM) have been in a bloody war for dominance at the mines that has resulted in violent strikes and assassinations.
Last year police trying to contain a wildcat strike shot dead 34 miners in one day at the neighbouring Lonmin mine in Marikana.
Eight NUM members were recently suspended at Lonmin for alleged union membership fraud.
The strike comes at an embarrassing time for the government, which on Friday tried to end 18 months crisis in the mining sector by drafting a pact with mining bosses and unions.
The deal which is to be signed on June 26, needs to be fine-tuned, said Vice President Kgalema Motlanthe, who led the talks.
Among the raft of plans contained in the draft deal, government, mining companies and unions said would commit to improve workplace relations and prevent strike actions from spiralling into violent conflicts.
The draft pact did not clearly state how it would avoid looming work stoppages at Lonmin mine.
Government has decided to wade in after the disputes continued to battered Africa's largest economy.
President Jacob Zuma last week assigned his deputy to restore calm in the industry after the country's economic growth hit a fresh low of 0.9 percent in the first quarter of 2013.
Mines are the country's largest private-sector employer, and their unionised workforce is a large source of votes for the country's ruling African National Congress.