Brazil's biggest state, Sao Paulo, declared new "code red" restrictions over COVID-19 Wednesday, ordering non-essential businesses closed for two weeks as an explosion of cases swept the country.
The partial lockdown, which will take effect Friday at midnight, (0300 GMT Saturday), bars all but "essential activities" in the state of 46 million people.
However, it allows schools and churches to remain open, along with health services, supermarkets and public transportation.
"We're going to face the two worst weeks since March last year," said Governor Joao Doria.
"Sao Paulo and Brazil are on the brink of a health system collapse."
Doria lashed out at his political rival, President Jair Bolsonaro, for the pandemic's latest surge in Latin America's largest country.
"This is your fault. It's because of your denialism," he said, addressing the far-right president in a press conference.
"More than 1,000 people are dying every day in Brazil. It's like five plane crashes a day.... Many of the Brazilians who have been buried died because you didn't do what you were supposed to: lead."
Doria, who is expected to mount a bid against Bolsonaro in the 2022 presidential election, had previously put his state on "code red" in late December.
Like many of Brazil's 27 states, Sao Paulo has seen its health system pushed to breaking point in recent days, with intensive care units nearly full and in some cases overflowing.
The sprawling country of 212 million people is currently having its deadliest week of Covid-19 since the pandemic began, with a daily record of 1,641 deaths Tuesday.
Brazil has the second-highest death toll in the pandemic, after the United Sates: more than 257,000.
Bolsonaro faces criticism for downplaying the pandemic, flouting expert advice on containment measures such as lockdowns and face masks, and his government's slow pace in vaccinating the population.