CAPE TOWN, South Africa — In an emotional address Monday night, South African President Cyril Ramaphosa reintroduced bans on public gatherings and alcohol sales, made mask-wearing required in public and lengthened a curfew as a second wave of coronavirus cases sweeps Africa's worst-hit country at "an alarming and unprecedented rate."

Earlier this month, South African scientists discovered a new variant of the coronavirus, similar to one found in Britain. Ramaphosa said it was “well established” throughout the country at this point. Testing positivity rates have soared above 30 percent nationwide, up from just 5 percent two weeks ago.

Cases of the South African variant have also been found in Britain, Finland and Switzerland, but Ramaphosa did not close the country’s borders as he had during its first wave.

Only a handful of countries have banned travel from South Africa. South Africa’s health ministry pushed back against assertions that its new variant is more dangerous than Britain’s, saying there was “no evidence” to support that claim.

On Sunday, South Africa passed 1 million coronavirus cases. More than 50,000 cases have been recorded since Christmas Eve — just under one case per 1,000 people nationwide.

“I beg you all” to follow the new measures, Ramaphosa said toward the end of his address, with tears in his eyes. He also asked South Africans to join him in lighting a candle at midnight on New Year’s Eve in remembrance of the more than 26,000 who have died of covid-19.

South Africa’s second wave will probably grow a great deal in the coming days. In some hot spots such as Cape Town, testing positivity rates have approached 50 percent. Researchers said the new variant is driving the surge.

“We have very strong reason to believe that this variant is much more transmissible,” said Tulio de Oliveira, director of the KwaZulu-Natal Research Innovation and Sequencing Platform, which coordinates analysis of genetic samples of the virus. “This variant has grown very fast, which means it has a high transmission, because it is dominating most of the infections. It is very unusual.”

Ramaphosa identified most of South Africa’s major cities as hot spots, including Johannesburg, Pretoria, Cape Town, Durban, Port Elizabeth and Polokwane. In the province of Eastern Cape, he said, the number of hospitalizations and in-hospital deaths had now surpassed the worst of the first wave, and most places in South Africa had yet to see the peak of the ongoing wave.

He also said 4,630 public health workers had contracted the coronavirus in December alone, partly due to the fact that the new variant is more transmissible, putting front-line workers at an even higher risk.

It’s unclear when vaccines will arrive in South Africa. The country is largely relying on the World Health Organization-led Covax facility, but Ramaphosa said Monday that his government was engaged in discussions with manufacturers, though he did not say with which or for what scale of vaccine purchase.

More so than in previous speeches, Ramaphosa seemed personally burdened by South Africa’s difficulty in flattening its curve of infections. The country makes up for more than 40 percent of all coronavirus deaths across the African continent — a figure health experts say is driven in part by South Africa’s higher proportion of people older than 65.

Early in the pandemic, South Africa imposed one of the strictest lockdowns in the world, with bans on sales of cigarettes and alcohol, nearly all travel restricted, and restaurants and bars closed. Even walking the dog could result in a ticket.

By September, new case numbers had dropped to around 1,000 per day. Recent days have seen more than 10,000.

On Monday night, Ramaphosa chastised some South Africans’ “extreme lack of vigilance during the holiday period,” and noted that many wear masks to gain entry into restaurants and shops, only to take them off once inside.

“We have let our guard down, and now we are paying the price,” he said.

All three of the country’s main private hospital groups said their intensive care units were under strain.

Richard Friedland, chief executive of Netcare, said the recent surge in coronavirus cases had “placed a significant and unprecedented demand” on health-care facilities.

Friedland warned that hospitals are being overwhelmed and may not be able to provide necessary care to new patients due to a lack of sufficient beds and equipment, such as oxygen tanks and ventilators.

“Practically, this may mean that levels of care such as ICU and high care, ventilators and oxygen delivery modalities may not be available to all patients,” he said.

Bearak reported from Nairobi.