• The electricity minister said that the leakages had caused the simultaneous failure of nine major power units.
• Two of the power units have returned to operations, resulting in the downgrading of power cuts by one level.
South Africa's Electricity Minister Kgosientsho Ramokgopa has ruled out claims that sabotage is behind the country's worsening power cuts.
Beginning last Wednesday, South Africa has been experiencing its most extreme power outages since November, prompting widespread outrage on social media.
The secretary general of the ruling ANC party Fikile Mbalula on Saturday alleged that the intensified power cuts were "clear sabotage" and called for "strong extra security measures".
Mr Ramokgopa rejected the claims on Sunday, saying that the extreme power outages had been caused by leaking boiler tubes, which are used in the generation of electricity in power plants.
The electricity minister said that the leakages had caused the simultaneous failure of nine major power units.
Two of the power units have returned to operations, resulting in the downgrading of power cuts by one level.
The remaining seven units are expected to resume operations early this week, but major load-shedding relief is expected when additional power units are added to the grid in March, Mr Ramokgopa said.
South Africa has been experiencing power blackouts - known as load-shedding - for several years.
Many residents often go up to six hours a day without power.
The intensified power cuts come just days after President Cyril Ramaphosa said that the end of load shedding was "finally within reach".