All 955 gold miners who were trapped underground for more than a day in South Africa following a power cut resurfaced unharmed on Friday, and were greeted by overjoyed relatives waiting at the site.

"Everybody's out," mine spokesman James Wellsted told AFP, adding that there were no deaths or serious injuries reported.

There were "cases of dehydration and high blood pressure but nothing serious", he said.

The miners were stuck in the Beatrix gold mine, in the small town of Theunissen near the city of Welkom, for around 30 hours after a massive power outage caused by a storm prevented lifts from bringing workers on the night shift to the surface.

After several hours engineers were able to restore power, allowing the hoist to bring up the miners -- who had been trapped since Wednesday evening -- in batches.

The workers were all brought to the surface within two hours.

"It was stressful, there was not enough ventilation," said mineworker Mike Khonto. "Thankfully our management managed to send us food and water."

Wellsted said there was "no indication so far that anyone has been in distress", although it was a "traumatic experience".

A young woman, who spent the night anxiously waiting near the mine for news of her uncle, could not hide her joy.

"We are relieved," she told AFP, without giving her name.

She had been among a group of miners' relatives who gathered along the road leading to the shaft, and who were kept at a distance by security guards as they awaited developments.

Several ambulances arrived on-site overnight, said an AFP reporter at the scene.

'Utterly unacceptable'

At sunrise the rescued workers still in their work suits and helmets, underwent medical check-ups and left by bus.

Despite the relief, the accident at Beatrix mine in Free State province, 290 kilometers (180 miles) southwest of Johannesburg, has reignited safety concerns at South African mines.

"We could have prevented it," said one mineworker who asked not to be named.

"They should have had some generators that were working. Security is the least of their worries. They only care about production," said the worker.

The National Union of Mineworkers (NUM) has called on mineworkers to refuse to work in "dangerous conditions".

"Major multinational corporations like Sibanye-Stillwater which should be industry leaders in creating a safety culture are doing far too little to prevent accidents," the union said in a statement overnight.

A parliamentary committee on mining expressed outrage at the incident, calling for "drastic" action against the company.

It condemned as "utterly unacceptable" the the lack of a backup plan to bring the workers to the surface.

The lawmakers on the committee called for "drastic actions to such acts of carelessness, including exploring possibilities of laying criminal charges against the management for attempted murder".

But mine spokesman Wellsted told AFP that "this was a very unusual event. The generators were affected by the storm."

Another group, the powerful National Union of Metalworkers of South Africa (NUMSA), said the mine should remain closed until a full investigation is conducted.

"They should not be allowed to operate until they can guarantee the safety of workers," NUMSA said in a statement.

Last August five mineworkers died after sections of a gold mine collapsed outside Johannesburg.

The country possesses rich mineral reserves and has some of the world's deepest gold mines.

Gold was for many decades the backbone of South Africa's economy, but production has declined sharply due to depletion of reserves.