At least 27 people have died after two separate shootings struck areas near Johannesburg and Cape Town.
Another 26 people were injured in the attacks, which happened within hours of each other.
Police are now searching for those responsible as questions grow over what led to the violence.
The first incident happened Saturday night at a tavern in Wedela, southwest of Johannesburg. Police said 17 people were killed and 15 others injured.
Reports said several armed attackers entered the area and opened fire before leaving the scene. Police said some victims were also robbed of their mobile phones.
Two vehicles were reportedly set on fire before the suspects escaped. No arrests had been announced in connection with the attack.
Police are also looking into possible reasons for the shooting. One line of inquiry involves a possible dispute linked to illegal mining.
Authorities are also checking whether the attack could have followed an earlier shooting at the same tavern.
Hours later, another South Africa mass shooting was reported in Lwandle, near Cape Town.
Ten people were killed and 11 others injured after gunmen opened fire at an entertainment venue. Five victims died at the scene, while five later died after being taken for medical care.
Police have not announced arrests in either case. Detectives are continuing their search for the suspects.
The motive behind the Cape Town shooting also remains under investigation. A possible business dispute has been mentioned as one line of inquiry.
The latest attacks happened days after another shooting near Durban left 11 people dead, including a pregnant woman.
President Cyril Ramaphosa condemned the latest violence and said security forces would continue efforts against criminality.
