Mudslides swept away shacks in Rio’s hillside slums, turning the city’s main lake and the sea brown during the heavy rains that started on Monday and continued to fall through most of Tuesday.
Most victims died in more than 180 mudslides, authorities said. Rio’s fire service said at least 40 injured people were taken to hospitals as the search went on for others reported missing, and that the death toll was certain to rise.
Brazilian president Luiz Inácio Lula da Silva, who was visiting the city on Tuesday, blamed local officials for not enforcing adequate building standards in areas prone to landslides, particularly in shantytowns.
“All we can do is pray to God to hold back the rains a little, so that Rio can return to normal, and so that we can set about fixing the things in the city that need fixing,” he told local radio.
The president said the work would include improved drainage systems.
Rio de Janeiro state has experienced a particularly hot and rainy summer this year, and meteorologists are forecasting more rain in the coming days. However, heavy rain is more common in January than in April.
Mayor Eduardo Paes warned residents to stay away from risky hillside areas and said public schools would stay closed for a second day on Wednesday as more heavy rain was forecast through the night.
“The situation is chaos” Mayor da Costa Paes said in a statement on Tuesday. “All the major streets of the city are closed because of the floods.”
“Each and every person who attempts to enter them will be at enormous risk,” he warned.
Mr Paes said the preparedness for heavy rainfall in Brazil’s second-largest city – which will host the 2014 World Cup and 2016 Olympic Games – was “less than zero”.
State governor Sergio Cabral meanwhile declared a state of emergency and urged people in high-risk areas to leave their homes. He told TV Globo that to stay inside would be “irresponsible” given the risk of new landslides.
Officials said 39 people died in metropolitan Rio, famous for its Carnaval and beaches, and 41 were killed in Niterói, the city on the other side of Rio’s Guanabara Bay.
The mayor said 1,200 people had been made homeless and that 10,000 houses remained at risk, mostly in the slums where about a fifth of Rio’s people live, often in precarious shacks that are highly vulnerable to heavy rains.
Morning flights in and out of the city of 6 million people were cancelled or seriously delayed and many neighbourhoods were cut off from power and transport.
Many companies shut down their offices for the day as torrents of water snarled traffic.