Correctional Services spokesman Manelisi Wolela has denied allegations that student leader Mcebo Dla.
More than 500 workers at a nickel mine in Mpumalanga face a bleak Christmas after they were told they no longer have jobs.
Though their contracts come to an end in September next year, mine authorities have notified contractors that their services with Nkomati Nickel Mine in Machadodorp, near Belfast, will no longer be required from as early as tomorrow.
Authorities say the current economic situation is to blame for their decision to end the workers' contracts.
The angry workers were not impressed by this and barricaded Badplaas road with rocks, burning tyres and anything they could lay their hands on.
The protest turned nasty and police were forced to use rubber bullets to disperse the workers.
Elukwatine police spokesman Constable Petros Mahlalela said four people were arrested for public violence.
"They were charged with malicious damage to property and public violence," he said.
The men will appear in the Badplaas magistrate's court today.
The workers say they have worked at the mine for five years now and their contracts, which were due to expire next September, had been abruptly terminated.
Business manager at the mine, Horst Jager, said due to the current financial situation, "it is unavoidable not to scale down as the price of nickel has dropped from $27000 (R270000) per ton to only $10000 (R100000)".
Fanky Mbethe, a shop steward for the National Union of Mineworkers, said they were not notified on time that they were going to be sacked.
"We are also angered by the fact that the mine, which also manages Pilanesburg Platinum Mine, is bringing back workers who were retrenched when platinum plants closed after the price of the metal dropped by 50 percent to replace us here," he said.