South African police have said that the planned opposition protests on Monday are not a mere shutdown but an attempt to overthrow the government.

The opposition party Economic Freedom Fighters (EFF) is organising nationwide marches to protest against the country's power crisis and has called on President Cyril Ramaphosa to resign.

"This is an attempt to overthrow the government. This is not a shutdown, but it’s anarchy," KwaZulu-Natal Police Commissioner, Lieutenant-General Nhlanhla Mkhwanazi, said on Friday while briefing media on security plans to deal with threats posed by the protests.

“The magnitude of threats differs from other planned shutdowns and that is why we have to be extra vigilant,” Mr Mkhwanazi was quoted by local media as saying.

He said police have received no notices of any planned gatherings in the province, adding that over 18,000 security officers would be deployed during the march, eNCA TV reported.

President Ramaphosa on Thursday warned that anarchy will not be tolerated during the protests and called on security forces to "defend our people".

Mr Ramaphosa said the only way to get him out of office and power is through a vote.

Julius Malema, the EFF leader, insists the protests are not illegal and has warned that anyone who attempts to stop them would "meet their maker", News24 reported.