The attacks come as South Africa grapples with persistent gun violence often linked to gang rivalries.
At least 27 people were killed in two mass shootings in South Africa's two main cities, police said on Sunday.
The first incident occurred Saturday evening when eight gunmen armed with assault rifles stormed a bar west of Johannesburg and shot 17 people and wounded 15 others.
The suspects opened fire on customers drinking outside and then moved inside to continue shooting, police said, where they killed 13 males and four females.
The motive for the shooting was still unknown, police said, adding that the suspects torched two vehicles before fleeing.
In a separate shooting at an entertainment venue in a township outside Cape Town early on Sunday, gunmen killed 10 people and wounded 11 more.
Five of the victims were declared dead at the scene while the others succumbed to their injuries while being taken to hospital.
No suspect has been arrested in either case, police said.
The attacks come as South Africa, awash with legal and illegal firearms, grapples with persistent gun violence often linked to gang rivalries and competition among informal businesses.
The country of about 62 million people records roughly 60 murders a day, among the highest rates globally.
In March, soldiers moved into violence hotspots in Johannesburg to support police efforts to tackle rampant crime, described by President Cyril Ramaphosa as one of the biggest threats facing the country.
South Africa has repeatedly turned to the army in times of crisis, from enforcing strict Covid-19 lockdowns in 2020 to deploying troops during the deadly riots sparked by the jailing of ex-president Jacob Zuma in 2021.
Soldiers were also sent into the streets in 2023 after a wave of truck burnings raised fears of wider unrest.