Johannesburg - Workers at South Africa's Lonmin platinum mine were returning to work on Wednesday night after union leaders called off an illegal strike sparked by the killing of a union leader last weekend.

“Workers, I say to you let us go back to work,” Joseph Mathunjwa, head of the Association of Mineworkers and Construction Union (Amcu), told thousands of cheering workers.

Amcu mineworkers had downed tools on Tuesday, demanding that a rival union, the once dominant National Union of Mineworkers, be ejected from the mine.

Amcu is also demanding recognition from the firm since it has overtaken NUM as the leading union at the mine.

“There are channels to be followed,” Mathunjwa said. “Go back to work so that your enemies will not take advantage of this situation.”

Workers were headed to the shafts to clock in for the Wednesday night shift.

“I am preparing to go underground right now because our president Mr Mathunjwa was here today and told us to go back to work,” worker Molisi Phele, told AFP on the phone.

Work had stopped at all of the firm's 13 shafts in the north-western Rustenburg mining town, the world's top platinum-producing region.

Lonmin welcomed the news that strikers had started returning to work.

“Returning to work and allowing engagement to continue through established channels is in everyone's best interest, especially in an unprotected action where the principle of 'no work no pay' applies,” Lonmin said in a statement.

Amcu leaders had initially distanced themselves from the strike, while NUM said their members were not part of it.

The two unions are locked in a vicious power struggle over who represents the majority of miners at Marikana, where 34 miners were shot dead by police last year.

NUM still enjoys Lonmin's recognition, despite losing scores of members to the more militant AMCU in the wake of the shooting.

“Still NUM is being treated as majority union at the workplace,” Mathunjwa told AFP earlier Wednesday.

Amcu will now take its fight for recognition to a the government labour mediation body and discussions were expected on Thursday morning.

Government expressed concern that workers went as far as embarking on an unprotected strike over a turn dispute.

“The issue that seems to have stoked the latest trouble are the kind of regular issues which should have been resolved without resorting to such drastic action like the downing of tools,” Labour Minister Mildred Oliphant, said.

“Workers must be aware that the unprotected strike could have serious consequences not only for themselves, but for the future of the mine and that of their jobs,” she said in a statement.

Tensions have been inflamed by recent violence at the volatile mine, with the unions blaming each other for the instability.

Amcu regional leader Mawethu Steven and two brothers, said to be members of NUM, were killed in separate incidents at the weekend.

“NUM is carrying firearms at the workplace wrongfully without being reprimanded by management,” alleged Mathunjwa.

Police have opened an investigation, but so far no arrests have been made.

The latest stoppage at Lonmin comes at the start of South Africa's so-called strike season when workers pour onto the streets demanding annual wage hikes.

Lonmin shares recovered almost one percent in London trade on Wednesday, only slightly up from a battering it received the day before. - AFP