More than 2,000 platinum workers returned to the surface at a South African mine on Wednesday after ending a three day underground protest over conditions, the owners said.All 2,205 workers who started the protest in two shafts about 500 metres below ground over bonuses and conditions were “now safely on the surface”, Impala Platinum Holdings said in a statement.More than 160 had returned to the surface during the protest because of the difficult conditions, the company, also known as Implats, said.All operations at the Bafokeng mine north of Johannesburg had been halted in the fourth major underground protest in South Africa in two months.The company, which also operates in Zimbabwe and Canada, did not say if it had made any agreement with the workers who it declared had staged an “illegal protest”.It did indicate that “disciplinary” action could be taken, however.Implats said it would be “instituting required disciplinary processes and securing the sustainability of the operation amid the low metal price environment.”Implats said the protest went ahead without union “support” and “against a background of increasing incidents of a similar nature at other mining companies.”It had previously said the protest put jobs at risk “given prevailing low platinum group metal prices”.The government has also expressed concern over labour unrest in the crucial mining industry which employs hundreds of thousands of people.South Africa is the biggest exporter of platinum and a major exporter of gold, diamonds, coal and other raw materials.More than 100 gold miners spent nearly three days underground in Springs near Johannesburg in October as rival unions battled for control.Another 440 staged a protest in another gold mine this month while 250 platinum workers demanding better wages occupied a shaft for three days at the same time. Â