Glencore Xstrata has fired 1,000 workers across three of its chrome mines in South Africa for going on 'illegal strike' last week.

The cull of workers has brought operations to a halt and the strike is still continuing but supplies to customers were not yet affected, said a spokesman for the Glencore Xstrata's chrome operations to Reuters.

"About 1,000 of the employees who have participated in the unprotected (illegal) strike have been dismissed," said Christopher Tsatsawane.

The strikes centre around the mining of chromium, which is a raw material used to produce ferrochrome and is a key ingredient to make stainless steel, near Steelpoort, north east of Johannesburg in Limpopo province.

South Africa holds around 75% of the world's chromite reserves

Glencore Xstrata said last week that the miners, most of whom belong to the militant Association of Mineworkers and Construction Union (AMCU), stopped work in solidarity of a colleague, who they claim, was assaulted by a shift supervisor.

South Africa has a long history of 'wildcat strike action', which is when strikes are taken place without the authorization of their trade union officials.

Those who fail to get formal approval can be sacked although employers often hire back most or all the workers they fire.

Glencore Xstrata's Tsatsawane added that "talks over the weekend between AMCU and the company failed to end the dispute and no other meetings were scheduled at this stage."

Other western mining companies regularly face wildcat strike from their staff.

Last month, Lonmin South African mineworkers went on a two-day strike in protest of the shooting of a senior union official, which led to 13 shaft production halt the mining town of Rustenburg.

By mid-May, a spokesperson confirmed that 83% of staff returned to work, over the course of two days.

The relevant spokesperson at Glencore Xstrata was not immediately available for comment when IBTimes UK contacted them.