A senior union official at a Lonmin mine in Marikana has been shot dead in South Africa in the latest violence to hit the country's platinum belt, a spokesman said Friday.

"A branch chairperson of the union was shot last night and killed," Lesiba Seshoka, spokesman for the National Union of Mineworkers said.

"He was attacked and a colleague of his was shot on the leg and is currently in hospital."

Police spokesman Brigadier Thulani Ngubane confirmed that a man was murdered in the informal residential area on Thursday night near the site where police gunned down 34 striking mining in August 2012.

"He was on the way to visit his girlfriend. He was then gunned down by four men who came out of nowhere," he said.

Ngubane said the victim was shot seven to eight times after his vehicle came under fire from four shooters and he got out of the car. He died instantly on the scene.

"The motive for the killing is unknown as this point," he said.

The man was chairman of the NUM's branch at Western Platinum which is one of four operations run by Lonmin in the Marikana area.

The north-western platinum belt has been the scene of a battle for supremacy between rival unions but the NUM did not want to speculate on what was behind the shooting.

"We do not know yet what the reasons are," said Seshoka.

The NUM was muscled out as the recognised union in July by the rival Association of Mineworkers and Construction Union (AMCU).

Seshoka appealed for calm and for the police to be given the opportunity to investigate the killing.

"Of course there may be a resurgence of violence, and this is what we don't want to see," he said.

Several union leaders have been killed since last year, with the most recent being another NUM local leader in August.