Impala Platinum, the world's number two producer, on Thursday fired 13,000 miners who went on an illegal strike in South Africa, the company said in a statement.

"Approximately 13,000 mining employees who participated in the illegal work stoppage at Impala Rustenburg... have been dismissed," parent company Implats said.

Miners downed tools on Monday demanding higher wages, grounding operations to a halt. Workers had been given until Wednesday to return to the job, the statement added.

Over the past month, the Johannesburg-based company has sacked a total of about 17,200 workers at its mine in the northwestern town of Rustenburg -- more than half of the 30,000 people employed in the town.

"There is no production at the mine," Implats spokeswoman Alice Lourens told AFP on Thursday.

"It's costing us in the region of 3,000 ounces of platinum a day."

Impala secured a court interdict against the strike and said it would fire those who still refused to work.

The company said it would rehire miners who wanted to reapply for work. Lourens could not say when this would start.

"We're still busy with the dismissal process," she said.

The company did not fear litigation because of the layoffs.

"It was an illegal strike because we were granted an interdict by the Labour Court," said Lourens.

The National Union of Mineworkers (NUM) on Wednesday accused Impala of breaking its promises to negotiate further on issues beyond the salary dispute.

Miners went on strike when some workers received an 18 percent salary increase, but certain categories of labour were excluded, said NUM spokesman Lesiba Seshoka.

Impala produced 941,200 ounces of platinum in the financial year which ended June 2011. It is Implats' biggest platinum operation.

The company as a whole produced 1.84 million ounces in the previous financial year.