A 25-year-old man shot and killed his wife and three relatives before turning the gun on himself in Mpumalanga yesterday.
Police say the suspect, Jonker van Deventer, arrived at the house on a farm near Plaston in White River.
He found his 34-year-old sister sitting with her two daughters.
"It is not clear what the two argued about when the suspect produced a gun and shot his sister and both children in the head," police spokesman Klaas Maloka said.
The children were aged 10 and 11.
"One child and the mother died on the scene, while the other child died in hospital," Maloka said.
He said after the shooting the suspect fled the scene but was later found dead in Barberton with a gun wound to his head and a gun next to him.
Maloka said a case of housebreaking was being investigated and an inquest docket was opened in Barberton.
"Investigations have so far revealed that the same guy had earlier shot his wife in the Kaapsehoop bushes in Nelspruit," Maloka said.
Last week a 50-year-old man shot his grandson, his daughter and then himself in Barberton.
Police said Joseph Madonsela, who lived with his family, phoned them and his friends to tell them that he was tired of living.
His 14-year-old son went to a neighbor and asked him to talk to his depressed father.
While the two were talking they heard three shots from inside the house.
They found the one-year-old grandson and the man's 20-year-old son shot in the head.
The son died on the scene, while the daughter is still fighting for her life in hospital.
The two also discovered the father with a gunshot wound to the head. He died on the scene.
Police are investigating a case of murder and attempted murder and are conducting an inquest into Madonsela's suicide.