Johannesburg - The deaths of eight miners at Harmony Gold's Doornkop gold mine, west of Johannesburg, should be investigated, Cosatu said on Thursday.

“The department of mineral resources... (should) conduct an immediate and thorough investigation into the accident, identify the causes, and assess whether there was any negligence on the part of the mine management,” Congress of SA Trade Unions spokesman Patrick Craven said in a statement.

“Immediate steps must be taken to make the mine safe before any work restarts.”

All operations at the mine, other than essential services, were suspended on Wednesday night after a fire broke out on level 192 of the mine, about 1700 metres underground.

The fire followed a seismic event on Tuesday which triggered a fall of ground.

Eighteen people were reported missing at the end of Tuesday's shift. One miner surfaced in the early hours of Wednesday and told rescue workers where the other miners he had seen underground were. Eight miners were brought to the surface unharmed later on Wednesday. Nine miners were still unaccounted for at the time.

On Thursday morning, the department said the bodies of eight miners had been found. One worker had not been found yet.

Craven said the tragedy should be a wake-up call for mine management to redouble efforts to reduce mine fatalities.

“Cosatu is shocked and saddened by the deaths. We send our condolences to their families and fellow workers.”

Mining fatalities declined from 123 in 2011 to 112 in 2012, but this was still too high, he said. - Sapa