Police said they could not yet confirm a motive but did not rule out a "feud between rival groupings." In a statement, they described how 13 men and one woman, thought to be pregnant, were inside the house when three men arrived and opened fire. The gunmen then set fire to a car belonging to one of the victims before fleeing, according to a reporter from local news channel eNCA, whose footage showed a burnt-out vehicle.
Authorities have launched a manhunt for the suspects. Police noted that some of those killed were on their watch list related to illegal activities, though they declined to elaborate "to protect investigations which have been launched."
The attack comes amid heightened anxiety in South Africa following the recent discovery of at least nine murdered women, with some bodies dumped by the roadside. The country has one of the world's highest murder rates — police data shows an average of more than 60 murders per day. Mass shootings, however, are a more recent phenomenon that have sparked fear and calls for stronger government action.
Last year, nine people died in a mass shooting at a tavern in Johannesburg. In February, President Cyril Ramaphosa described organised crime as "the most immediate threat to our democracy, our society and our economic development" and announced the deployment of the army to support police.
Rivalry among criminal gangs over turf, drug trafficking and illegal mining is common in South Africa and often drives violence within communities.