The shooting took place in KwaMakhutha Township south of Durban, the South Africa-based television news channel eNCA reported, noting that a pregnant woman was among the victims, Anadolu Agency reported.
Ten victims died at the scene of the attack, while another individual succumbed to injuries while being transported to a hospital.
The victims were gathered inside a residential property in the township when unidentified assailants stormed the premises and opened fire before 11 pm local time (2100GMT) on Tuesday.
Before fleeing the scene, the attackers set ablaze a vehicle belonging to the homeowner.
The motive behind the fatal assault remains unknown, and authorities have not announced any arrests or identified the suspects.