SECURITY guards and police officers shot and killed three people during an invasion of an Aquarius Platinum mine near Rustenburg on Wednesday.
Aquarius recently suspended two mining operations because of weak platinum prices, high costs and operational difficulties that are affecting the entire platinum mining sector.
Following a protest at the Kwezi shaft at Aquarius's Kroondal mine, three people died of wounds sustained from buckshot fired by security guards. Another 20 were wounded.
Kroondal is Aquarius's only remaining operational mine in South Africa. The Kwezi shaft accounts for a fifth of the mine's production, which was 415,000oz of platinum group metals in the year to the end of June.
A protest against the dismissal of 260 people by mining contractor Murray & Roberts earlier this year turned nasty after the Commission for Conciliation, Mediation and Arbitration upheld the company's decision to fire those workers for participating in an illegal strike.
"A gathering of approximately 200 people, some of whom were armed, forced their way onto the mine property," Aquarius said in a statement on Wednesday.
"Members of the private security company under contract to the mine attempted to disperse this unruly crowd as the actions of the group, which included the throwing of petrol bombs, threatened both mine employee lives and property.
"It is confirmed that three people have died and at least 20 others were injured in this incident. The people are understood to be former employees of the mine's mining contractor, who were dismissed following illegal strike action in June."
Work at the shaft was suspended and Aquarius would decide on Thursday whether to restart it, a company spokeswoman said.
There has been labour unrest involving Murray & Roberts Cementation employees at Aquarius mines since 2007, with thousands of ounces of platinum lost to industrial action.
In November 2009, police arrested 32 Murray & Roberts Cementation workers after they invaded a shaft at Kroondal and attempted a sit-in marked by violence against other workers.
Police said at the time that booby traps using underground explosives had been set up by the invaders and three police officers were wounded in an underground explosion.
This was why Aquarius security guards reacted the way they did on Wednesday - to prevent another shaft invasion, the spokeswoman said.
National Union of Mineworkers spokesman Lesiba Seshoka said the union did not condone the violence and wanted an investigation into Wednesday's events.
Aquarius moved to owner mining instead of using Murray & Roberts Cementation as its contract miner. This is one of the decisions it took to reduce costs at the Kroondal mine it shares with Anglo American Platinum (Amplats).
There are upfront costs to establish an owner-mining operation. These have caused friction with Amplats, which is conducting a review of its business to restore profit margins.
Aquarius shares fell 2.75% on the JSE on Wednesday to R4.95 each.