A FEMALE Mpumalanga police constable shot dead her husband's first wife and her 19-year-old daughter - before turning the gun on herself.

The unidentified 31-year-old police officer also shot and wounded their domestic worker during the incident.

The police officer allegedly went to the home of the first wife Athol village near the Manyeleti game reserve and shot the 42-year-old woman on Friday afternoon .

Provincial police spokesperson Superintendent Abie Khoabane said the domestic worker and first wife's daughter tried to intervene but the constable turned the gun on them, and wounded them.

While the three people were lying on the ground, the enraged woman then torched the house before turning the gun on herself.

Neighbours managed to take the seriously injured domestic worker and daughter to hospital, but the girl later died in hospital.

"We do not know the motive for the shooting. We are investigating two murders, an attempted murder and arson," Khoabane said yesterday.

Sowetan has reliably been informed that the husband was planning to marry a third wife and that this did not go down well with the police constable.

A colleague of the constable, who asked not to be identified, told Sowetan that the policewoman called to inform her that she had shot people and burnt her husband's house.

The husband, a municipal manager, got the shock of his life when he arrived back from work to find his two wives dead.

Meanwhile, a Barberton prison warder shot and killed his girlfriend and her friend before turning the gun on himself on Friday.

Khoabane said that he did not know the motive but police were investigating. "We have confiscated both firearms and we will send them to Pretoria for ballistic tests, the results of which will form part of our investigations."

He asked people with domestic problems not to opt for violence but to talk to priests, employers, and to seek counselling.