Sibanye-Stillwater said on Thursday more than 1000 miners are stuck underground at its Beatrix gold mine in South Africa after a storm knocked out power, but they were not in danger.
On Thursday, spokesman James Wellsted said the miners were safe and receiving food and water.
Power was being restored to the mine but there was not yet enough to bring the miners to the surface.
The National Union of Mineworkers said 65 mineworkers had been rescued but more than 1000 remained underground.
"There is no electricity there, so they are using a generator to power the cage to take workers to the surface," NUM spokesman Livhuwani Mammburu told Reuters.
"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."