Mudslides swept away shacks in Rio city's hillside slums, turning the main lake and the sea brown of Brazil’s second largest city 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.

Mayor Eduardo Paes warned residents to stay away from risky hillside areas and said public schools would stay closed for a second day on April 7 as more heavy rain was forecast through the night.

Officials said 39 people died in metropolitan Rio, famous for its Carnival and beaches, and 41 were killed in Niteroi, 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.

Reuters