Two farm workers were shot dead when their employer found them assaulting his 79-year-old grandmother following a wage dispute at a farm in De Deur near Vereeniging, police said on Thursday.

One of the two men, a 22-year-old, had had a confrontation with the 26-year-old farmer who refused to pay his workers their monthly wages, Constable Magauta Serati said.

“The employer eventually paid the man after the man had threatened to do something terrible once he returns to the farm.”

After giving his employee the money, the farmer fired him.

The man returned to the farm on Wednesday evening accompanied by another farm worker and both assaulted the farmer's grandmother.

When the farmer returned home, one of the two men fired a shot at him and he returned fire killing both men.

They both died on the scene and the farmer did not sustain any injuries.

The elderly woman was seriously injured and rushed to hospital.

A double murder and an attempted murder case were being investigated. - Sapa