Seventeen people were killed when eight gunmen stormed a bar close to Johannesburg on Saturday evening, with 15 more injured.
In a separate shooting in the early hours of Sunday morning, 10 people were killed outside an entertainment venue in a township near Cape Town and a further 11 were injured.
South Africa has one of the highest murder rates in the world and has struggled to contain gang-related gun violence in recent years. Police have not given a definitive motive for either of the latest attacks.
In Johannesburg, gunmen opened fire on customers outside the bar before continuing the attack inside and torching two vehicles before fleeing.
Police said thirteen men and four women were killed.
Gauteng Police Commissioner Lt Gen Tommy Mthombeni said people from Ethiopia and Lesotho were among those caught up in the shooting, but that the vast majority were South African.
He also said police believed the motive behind the shooting was robbery, as personal belongings had been taken, but that they could not rule out turf wars between illegal mining groups.
MNA