A South African company has fired 8,500 mineworkers who ignored an ultimatum to end an illegal strike and return to work.

The Gold Fields mining firm said Tuesday it was dismissing the strikers, who worked at its KDC East mine near Johannesburg. The company said the workers had 24 hours to appeal their dismissals.

South Africa's mining industry has been reeling from a series of strikes and protests since August, when police opened fire on striking workers at a platinum mine and killed 34 people.

The workers at that mine eventually won a 22 percent pay raise, spurring workers at other mines to demand better pay and work conditions.

Last week, Gold Fields resolved strikes at two other mining sites through ultimatums that workers must return to the job. Gold Fields said strikes have cost the company at least $137 million in lost revenue.