President Cyril Ramaphosa on Sunday oversaw the release of dozens of South Africans who had been in quarantine since returning from Wuhan in China earlier this month.

South Africa, which has the highest number of infections of any African country, was on Sunday observing the third day of its 21-day lockdown to halt the spread of the virus.

Ramaphosa went to a remote resort near Polokwane city in the northern Limpopo province to free the 114 South Africans who had been isolated since March 14 when they were evacuated from China.

The group had been working and studying in Wuhan, then the epicentre of the virus, which was placed under lockdown for more than two months after the novel coronavirus was first detected in December.

Ramaphosa ordered their repatriation late last month, responding to calls from their families.

They were all free of the deadly novel coronavirus on their return but still quarantined.

Ramaphosa said the group - having been under quarantine in Wuhan for 51 days and a further 14 days in South Africa - were proof that lockdowns were the right strategy.

"You are the best campaigners for a lockdown because you more than anyone else have seen that a lockdown does work.

"As you go back tomorrow ... we would like you to spread the word that you were able to be coronavirus free in China because you were locked down and you continue to be coronavirus free.

With 1,187 confirmed infections and one death, South Africa has the highest numbers of confirmed infections on the continent.

Ramaphosa has ordered a 21-day lockdown for the country's 57 million inhabitants, deploying police and the military to enforce restrictions.

But authorities often struggle to get people to comply.

"This lockdown must be taken seriously by our people," said Ramaphosa on Sunday. (AFP)