The mayor of South Africa's commercial hub, Johannesburg, has gone into self-isolation after a member of his staff tested positive for coronavirus.

A statement from Geoffrey Makhubo's office said he was taking the precautionary measure until the results of his test are known.

He had previously returned a negative test.

All staff at his office have also undergone tests after the latest case.

"The mayor will continue to monitor and provide guidance on work currently being carried out to contain and manage the spread of Covid-19 in the city whilst in self-isolation," the statement by his spokesperson said.

South Africa has the highest number of confirmed coronavirus cases in the continent.

President Cyril Ramaphosa on Monday urged South Africans not to be scared by the rising numbers after the country recorded more than half of the current total number of cases in the last two weeks.

Schools in South Africa have begun gradual resumption of the school year with grade 7 and 12 learners returning to school on Monday. Places of worship have re-opened but with strict guidelines to prevent the spread of coronavirus.