Health emergency coordinator Fernando Simon blamed the surge on lax restrictions over the Christmas holidays and said he expected the increase to continue for some time.
South Africa's health ministry reported more than 21,000 new infections late on Wednesday, taking confirmed COVID-19 cases to date to 1.15 million, the most in Africa.
After dipping below 200 cases per 100,000 people in early December, the coronavirus' incidence increased steadily to reach 321 cases per 100,000 on Thursday.
"We need to restrict contact more strictly... We ask all citizens to restrict contact to the absolute minimum," she told journalists following a meeting with the leaders of Germany's 16 federal states.
Italy has seen an official total of 73,029 COVID-19 deaths since its outbreak came to light on Feb. 21, the highest toll in Europe and the fifth highest in the world.
The daily tally of new infections increased by 19,037 from 18,040 the day before, taking the total number of cases since Italy's epidemic began to 2.02 million.
Around half the 72 locally transmitted cases reported were linked to an outbreak discovered at the weekend at a seafood centre near the capital Bangkok, the ministry said in a statement.
The British government will review whether it needs to impose its strictest COVID-19 restrictions on more of the country on Wednesday as a highly infectious variant continues to spread but will not change Christmas rules.
Britain reported a record number of new infections on Tuesday as a mutated strain of the coronavirus, which could be up to 70% more transmissible than the original.
The country of 10.7 million had one of the sharpest spikes in COVID-19 infections at the end of October when weekly case levels were about twice as high as now.
India exceeded 10 million infections of the new coronavirus on Saturday, much later than predicted only a month ago as the pace of infections slows, despite many in the country giving up on masks and social distancing.
After hitting a peak of nearly 98,000 daily cases in mid-September, daily infections have averaged around 30,000 this month.
Australia has avoided the worst of the pandemic due to border closures, lockdowns, widespread testing and social distancing. It has recorded a total of around 28,100 infections.