South Africa, the worst-hit country in the continent, has entered a third Covid wave, with new daily cases doubling over the past two weeks.

Gauteng province -- home to the administrative capital Pretoria and financial hub Johannesburg -- is the outbreak's current epicentre, accounting for around 60 percent of the latest daily increase.

"We have requested additional capacity to assist Gauteng in terms of military help," acting Health Minister Mmamoloko Kubayi-Ngubane said at a virtual press briefing on Friday.

The deployment will start "from today," she said.

The military will provide support for health workers and help with community testing and contact tracing.

Daily infections jumped by 13,246 on Wednesday, the highest in five months.

Hospital admissions have increased by nearly 60 percent over the past two weeks.

To date the country has recorded over 1.7 million cases, of which at least 58,325 have been fatal.

President Cyril Ramaphosa earlier this week slightly tightened restrictions to curb the spread of infection and ease pressure on hospitals.

The third infection wave has struck as South Africa is struggling to roll out its vaccination programme.

Only around two million single shots have been administered since February. The government's declared target is to fully vaccinate over 40 million people by the end of 2022.

Inoculation has so far only been open to health workers and over-60s, although teaching, police and military staff are set to receive their first jabs this month.

More than 70,000 military troops were deployed to help enforce strict lockdown measures at the start of South Africa's coronavirus outbreak last year.

The soldiers returned to their barracks in October.