The World Health Organisation voiced alarm on Monday at the spread of COVID-19 in Africa, warning that South Africa's surging numbers could be a "precursor" for outbreaks across the continent.

"I am very concerned right now that we are beginning to see an acceleration of disease in Africa," WHO's Emergencies Chief Michael Ryan told a virtual press conference.

Until recently, Africa had remained relatively unscathed by the pandemic compared to the surging numbers seen in other parts of the world.

With more than 15,000 deaths and close to 725,000 cases, the continent remains the world's second least affected after Oceania.

But the situation has become increasingly worrying, particularly in South Africa.

The country, which over the weekend saw its death toll from the novel coronavirus pass the 5,000 mark and which has registered well over 350,000 infections, is by far Africa's hardest-hit.

But Ryan warned that the situation there could be seen as "a warning" for what the rest of the continent might have in store.

"While South Africa is experiencing a very, very severe event, I think it is really a marker of what the continent could face if urgent action is not taken to provide further support," he said.

"South Africa may unfortunately be a precursor, it may be a warning for what will happen in the rest of Africa."

'A wake-up call' 

Ryan pointed out that South Africa's outbreak began earlier than those in a number of other African countries. It had first spread in wealthier areas but had now moved to poorer and more rural areas, he said.

"Therefore, South Africa is experiencing that acceleration," he said, stressing though that the acceleration was no faster than elsewhere on the continent.

While South Africa's numbers were by far the largest, they had "only" increased by 30 per cent in the past week, he said.

By comparison, numbers in Kenya had increased by 31 per cent, in Madagascar by 50 per cent, in Zambia by 57 per cent and in Namibia by 69 per cent, he pointed out.

"I think what we are starting to see is a continued acceleration of transmission in a number of countries," he said.

"This isn't just a wake-up call for South Africa... We need to take what is happening in Africa very, very seriously."

Ryan pointed out that a number of the countries experiencing the greatest increases were wracked "fragility and conflict", urging international "solidarity and support".