Stage 6 loadshedding will remain in force until further notice, Eskom said late on Thursday.

"The extension of loadshedding is caused by further breakdowns of generation units and continued shortage of generation capacity due to delays in returning to service some generation units," the power utility said.

Breakdowns have increased to 18 617 MW of generating capacity while the generating capacity out of service for planned maintenance is 5 807 MW.

Over the past 24 hours two generation units were returned to service at Camden Power Station, but at the same time, generating units at Duvha, Kendal, Medupi and Tutuka Power Stations were taken offline for repairs.

There have been delays in returning a unit to service at Kendal, Lethabo, Medupi and Tutuka power stations.

"The team is working around the clock to ensure that these units are returned to service as soon as possible," Eskom said.