Eskom on Friday obtained a court interdict prohibiting the intimidation of workers and contractors who are not part of an ongoing wage strike, as well as the highjacking of coal trucks and the sabotaging of the power utility's electricity infrastructure. 

On Thursday, generation and distribution of electricity across Eskom’s network was constrained as thousands of workers picketed across its power stations and at its headquarters against the freezing of wage increases this year. 

Workers affiliated to the National Union of Mineworkers (NUM) and the National Union of Metalworkers of South Africa (Numsa) are angry over the cash-strapped company's decision not to increase salaries this year. They have demanded a 15 percent hike.

There were reports of road blockades, attacks on staff, and wilful damage of electricity infrastructure, and road coal deliveries had to be stopped for security reasons as the picket continued mostly at the Mpumalanga power stations.

The Labour Court declared that the strike, picket or march was "unprotected and unlawful" and ordered the NUM, Numsa, and fellow union Solidarity and their representatives not to participate. Trade unions have not yet responded to the ruling.

As a result of the protest, Eskom implemented loadshedding on Thursday evening, plunging several Johannesburg suburbs into darkness as generation and distribution across its network came under pressure. 

On Friday morning the power utility said the system was relatively stable, with no load-shedding anticipated for the most part of the day.