South African trade unionists were left "shocked and angered" by the latest murder of a worker in Marikana.

Former National Union of Mineworkers (NUM) shop steward Percy Letanang was shot seven times on Sunday. He died in hospital on Tuesday.

Trade union federation Cosatu sent "its heartfelt condolences to his family, friends and comrades on their loss."

Mr Letanang took voluntary severance from the violence-wracked Lonmin platinum mine in Marikana after the company derecognised the NUM.

He was the fourth NUM member to be killed in the Rustenburg area in less than three months, Cosatu describing the death as a "continuation of what are clearly deliberate assassinations."

The area has been tense since last August when non-Cosatu affiliate ACMU attempted to gain members in the mine amid unofficial strike action.

Violent clashes between the two sides and police resulted in the deaths of 44 people - 34 of them on August 16 - in what became known as the Marikana massacre when security forces opened fire on striking workers, many of whom appeared to be running away.

The massacre caused an uproar in South Africa and around the world.

Ministers, employers and most unions signed a deal on July 3 acknowledging that there was "an immediate crisis of violence and anarchy in and around the mines."

Cosatu demanded that police and prosecutors "do everything possible to implement that agreement so that people can walk in the streets in safety and enjoy their constitutional human right to move freely without fear of attack."