Gunmen stormed a home in a township outside the South African city of Pietermaritzburg and killed 10 members of the same family, police have said.
Police did not give a motive for the shooting.
Seven women and three men were killed, the police ministry said in a statement.
South Africa has one of the world's highest murder rates, with about 20,000 murders recorded every year out of a population of 60 million.
"It's a crime scene, terrible. Too many people were lost here," Police Minister Bheki Cele said in comments broadcast on public broadcaster SABC from Pietermaritzburg in KwaZulu-Natal province.
Cele said police management needed to sit down to talk about whether the province needed more police resources.
A Reuters photojournalist at the scene of the shooting saw a mortuary van in the yard of the homestead into which bodies of those killed were being loaded on a stretcher. Worried members of the community looked on.