Two mineworkers have been killed at Harmony Gold's Kusasalethu gold mine outside Carletonville.
Company spokesperson Henrika Basterfield says investigations into the cause of the accident are underway.
Operations at the gold mine have been temporarily suspended.
The National Union of Mineworkers says the pair died in a "mud rush".
On Friday, a worker died at the Impala Platinum mine in Rustenburg, and another at Harmony Gold's mine in the Free State.