Johannesburg - Eskom is investigating a major incident that took place at Unit 5 of the Lethabo power station in the Free State on Wednesday afternoon, the power utility said in a statement.

"We can confirm that there are injuries but cannot confirm further details at this stage. Management's first priority is to ensure the safety of all staff on site. More information to follow as details become clearer," Eskom said.

Meanwhile, an Eskom customer network centre or depot in Orange Farm, Gauteng, was evacuated earlier on Wednesday following the damage to the building and vehicles caused by angry protesters who were against the audits being done on electrical installations and the removal of illegal connections.

Eskom has experienced similar protests in other parts of Gauteng, with the most recent incidents happening in Diepsloot, Protea Glen, Katlehong, and Winterveldt.

Orange Farm area has been experiencing power outages in recent months due to overloading of transformers, which usually explode due to pressure from illegal connections.