Hundreds of workers are trapped underground in a gold mine in South Africa after a thunderstorm caused a lift to break down.

More than 1,000 miners are awaiting evacuation from the Beatrix mine in Free State province, some 122km (76 miles) north of the city of Bloemfontein.

The workers were safe and receiving food and water, said a spokesman for mine operator Sibanye-Stillwater which is the largest individual producer of gold in the country.

However, mine unions have expressed concern that some workers have chronic conditions and lack access to medication.

Livhuwani Mammburu, from the national union of mineworkers, said: "There is no electricity there, so they are using a generator to power the cage to take workers to the surface.


Image: Sibanye is the largest single gold producer in South Africa

"The problem is they are rescuing one mineworker at a time. It is very slow. It is worrying. Some of our members have chronic conditions and they don't have medication down there."

James Wellsted, a spokesman for Sibanye-Stillwater, said the thunderstorm had resulted in a power outage, which had stopped the shaft lift from working.

"We sent rescue teams down, accounted for all the people and obviously are trying to get them out of there as soon as possible," he said.

"We are having some issues - probably related to the power surge linked to the storm - in getting the winders working, so we are busy working on that issue at the moment.

"Last night there was a severe storm in the Free State that affected two different power cables... and cut off all electricity supply to the mine, so we were unable to bring the night shift up.

Image: Sibanye operates gold mines across South Africa, including this one in Westonaria

"All employees appear to be fine. We are supplying food and water."

Sixty-five people were rescued during the day, but as many as 1,200 are still thought to be trapped.

In total, it employs about 9,500 people and the deepest operating level is about 6,740ft (2,055m).

South Africa possesses rich mineral reserves and has some of the world's deepest gold mines, but production has declined sharply in recent years due to depletion of reserves.