A spokesman for Gold Fields says the company has fired 8,500 South African miners who have been striking at one of its operations outside Johannesburg.

Sven Lunsche said on Tuesday that the miners, who have been striking since Oct. 14, have until Wednesday to launch an appeal. Gold Fields, one of the world's top producers of gold, on Monday issued an ultimatum to workers at its KDC East operations in Carletonville to return to work by Tuesday or face dismissal. The ultimatum was similar to the one issued earlier by Anglo American Platinum (Amplats), which fired 12,000 workers for staging an illegal strike. The fired miners say they will make it difficult for Amplats to hire new workers.

Lunsche said Gold Fields had beefed up security to prevent violence.