"An unemployed cousin of a NUM shop steward was shot and killed last night [Saturday] at the shop steward 's house in what is reported to be a case of mistaken identity," spokesman Lesiba Seshoka said.

"Gunmen appeared from nowhere at the Marikana hostel and immediately shot the steward 's cousin who was sitting on a bed. The cousin died on the scene."

Seshoka said the shop steward was not at home but his cousin and a friend were. The friend witnessed the shooting, he added.

He said the union was worried as this was not the first death connected to the union.

On Friday night, a NUM branch leader was shot dead at his home in Marikana, in what Seshoka described as an "assassination".

"This comes after the death of the NUM branch chairperson last weekend and the attack on another branch leader, who escaped whilst his wife was killed," said Seshoka.

Five NUM members -- two of them shop-stewards -- were killed in violence associated with a strike at Lonmin's platinum mine in Marikana between August 10 and August 16, said Seshoka.

Of the 34 people shot dead by police trying to disperse a group of protesters on August 16, 14 were NUM members, he said.

On September 11, a third NUM shop steward was found dead near the scene of this shooting. Dumisani Mthinti had been hacked to death.

Striking workers at Marikana -- and other mines -- have voiced unhappiness with their NUM representatives.

During an inspection in loco by the Farlam commission of inquiry into the Marikana shooting, a worker claimed NUM members confronted and shot workers -- killing two of them -- who were marching to the union's office on August 11.

The strike at Marikana was initially thought to be linked to a struggle for recognition between the NUM and the newly-established Association of Mineworkers and Construction Union (Amcu).

When the violence broke out, each accused the other of inciting the violence. Amcu claimed the NUM resorted to violence to throw people into disarray whenever it lost members.

Seshoka said NUM would be calling for a meeting with the police to discuss safety of union members.

"This is one too many deaths. After the height in Marikana we have seen a lot of people hacked. Just too many," he said.

"The NUM is highly perturbed by the inefficiency of the police in that of the many cases reported in Marikana, there is yet to be any progress in the arrest and prosecution of any suspect."

The North West police confirmed a shooting on Sunday afternoon but further details were not immediately available.