A mine worker is seen underground at a mine outside Johannesburg.
"Gold Fields Limited regrets to report that five employees have lost their lives at the 4 Shaft (Ya-Rona) KDC West mine, near Merafong … when a fire broke out [on Saturday] night," spokesperson Sharda Naidoo said on Sunday morning.
Fourteen other workers were admitted to hospital for routine observation and were in a stable condition, she said.
"The entire KDC mine has been closed until further notice."
Mine management "deeply regrets" the accident and an investigation was under way.
Earlier, spokesperson for the National Union of Mineworkers (NUM) Lesiba Seshoka said the five died from smoke inhalation while working overtime doing mudloading. Early indications were there was no compressed air in the section where they were working, he said.
The NUM's general secretary, Frans Baleni, said: "We strongly condemn the company for sending workers on overtime night shift when there is no ventilation."
The union called on the department of mineral resources to investigate the alleged safety lapses. – Sapa