Escalated blackouts in South Africa should taper off by mid-week as the affected units are brought back online, the electricity minister said.

The country saw its most severe nationwide power cuts in months starting on Saturday, after state-owned power utility implemented so-called stage-6 load shedding — that is, taking 6GW of demand off the grid.

Electricity minister Kgosientsho Ramokgopa said on Sunday that the escalated level of load shedding were the result of nine generating units, which contribute 4.4GW to the grid, going offline owing to boiler tube leaks.

“It was like four stages of load shedding essentially imposed on us as a result of result of these boiler tube leaks,” Ramokgopa said at a regular briefing.

The minister said the utility’s management will work directly with the original manufacturers of the tubes to ensure that Eskom is able to better diagnose problems and deal with them quickly. This will allow the utility to return the units to service within the shortest possible period, Ramokgopa said.

“We have already returned 1 000MW, and we expect the last of these units that failed” to return to operation by Wednesday, the minister said. At that point, while power outages are likely to continue, they should be no higher than stage 4, he added.