Video obtained by Reuters showed rising water flooding streets and rivers and submerging houses in the small town of Mucum, in Rio Grande do Sul, the country's southernmost state. Nearby cities such as Lajeado and Roca Sales were also hit severely.
Dominguez Fontana, a 74-year-old sawmill worker who escaped the Mucum flooding, said nothing could be salvaged.
An aerial view of destroyed houses surrounded by mud, along a glimpse of a brown river.
President Luiz Inacio Lula da Silva said on Wednesday he had spoken to Rio Grande do Sul Gov. Eduardo Leite to offer the federal government's full support to help the state "face this crisis."
Lula sent two ministers to the state to oversee search and rescue efforts and said Vice-President Geraldo Alckmin would also be on standby to travel there.
Search and rescue teams had been focusing around the Taquari Valley, about 150 kilometres northwest of the state capital Porto Alegre, where most of the victims and damage were recorded.
Video footage showed families on the top of their houses pleading for help as rivers overflowed their banks. Some areas were entirely cut off after wide avenues turned into fast-moving rivers.Overflowing rivers flood homes as deadly storm batters southern Brazil
A cyclone has caused devastating floods in several cities in southern Brazil. Authorities say the storm has killed dozens of people and left more than 1,600 homeless.
In Mucum, a city of about 50,000 residents, rescuers found 15 bodies in a single house.
"The water arrived very fast; it was rising two metres an hour," Mucum resident Marcos Antonio Gomes said. "We have nothing left. Not even clothes."
Gomes, a 55-year-old businessman, said that it was the fourth time in 15 years that his house was damaged by floods. He said this one was the worst so far, and he expected more flooding in the future."There's no way we can live here," Gomes said. "This will come back. We have to abandon."
Weather forecaster Climatempo said that even though showers had stopped on Tuesday, they were expected to return to Rio Grande do Sul on Wednesday and Thursday before dissipating by Sunday, with the state still on alert for floods.
"A combination of lower air pressure and the accumulation of warm humid air will again generate heavy clouds over Rio Grande do Sul, which will cause more heavy rain," Climatempo said in a statement.
The floods in Rio Grande do Sul were the latest in a series of such disasters to have recently struck Brazil, where more than 50 people were killed in Sao Paulo state earlier this year after massive downpours caused landslides and flooding.
Three people are shown digging through the remnants of debris from a destroyed house.
Marcos Gomes, second from right, searches for belongings at the site of his destroyed home in Mucum on Wednesday. (Wesley Santos/The Associated Press)
The colonial-era city of Petropolis near Rio de Janeiro and Bahia state also suffered similar disasters recently, as well as Santa Catarina, a state neighbouring Rio Grande do Sul where an additional victim was confirmed on Tuesday.
Rio Grande do Sul was hit by another extratropical cyclone in June, which killed 16 people and caused destruction in 40 cities, many of those around Porto Alegre.
The state is home to some 10.9 million people and hosts several industries, in addition to being among the top grain-producing states in the country. It borders Uruguay and Argentina.
The death toll from heavy rains that devastated Brazil's Rio Grande do Sul state rose to 31 on Wednesday, local authorities said, as an extratropical cyclone batters the region, flooding homes and swelling rivers.
Video obtained by Reuters showed houses in the small town of Mucum submerged by rising water, while streets and rivers were flooded. Nearby cities such as Lajeado and Roca Sales have also been severely affected. The floods in Rio Grande do Sul were the latest in a series of such disasters to have recently struck Brazil.
