Sibanye-Stillwater said on Friday that all the miners who were trapped underground at its Beatrix gold mine in South Africa had been brought to the surface.

Company spokesperson James Wellsted said 955 miners, trapped after a storm knocked out power, had been freed.

The National Union of Mineworkers said another 65 workers had previously been rescued.

"Everyone is fine, there were minor injuries and a bit of dehydration but that's all," said Wellsted.

The incident highlights safety concerns in an industry that is home to the world's deepest mines, with workers at some sites operating at depths of up to four kilometres.