Two of the last three trapped mineworkers at the Sibanye-Stillwater mine in Driefontein have been located, mine spokesperson James Wellsted said on Friday evening.
"We've got sight of the two of them and we have a good idea of where the third is, which should make the recovery process a bit quicker," he said.
He said the rescue operation would go on through the night.
When asked if they were still alive, he said that had not been established yet.
"I think the chances are getting more and more slim given the amount of time that they have been trapped. But we will continue trying to get them up," said Wellsted.
Wellsted earlier said that a seismic event, which occurred at about 13:30 on Thursday afternoon, caused a fall of ground in an operating stope.
Mine rescue teams were immediately mobilised and three workers were located and were interacting with the rescue teams.
Four dead
On Friday afternoon, the mine was hit by another two seismic events.
The seismic events measured 3.4 and 2.0.
Four mineworkers were killed after the seismic event on Thursday while six others had to be hospitalised.
Earlier this year, 955 miners were trapped following an electricity outage at the Sibanye Gold mine in Welkom.
A week later at the Kloof Ikamva shaft, two mineworkers were found dead after a fall of ground caused by a seismic event.
The following week a mineworker died at Sibanye Stillwater's Masakhane shaft when a box of gold ore crushed him to death.
Wellsted said there had been seven fatalities at Driefontein this year. This includes this week's four deaths.
He said there had been two fatalitiesa year since 2013 to 2018 at the mine.