SAO PAULO: The death toll rose to 143 from the worst extreme weather to ever hit south Brazil's Rio Grande do Sul state, with 125 people missing and more than 600,000 evacuated, the Civil Defence agency said.

In two weeks of record rainfall that has unleashed flooding and mudslides across the state, 446 towns have witnessed dramatic scenes of survivors rescued from floodwaters, including in the state capital Porto Alegre, where the Guaiba river burst its banks, inundating more than half of the city, Xinhua news agency reported on Sunday.

Downpours began on April 29 and continued on Sunday, erasing hopes of floodwaters receding, and raising the number of the displaced from about 441,000 on Saturday to 618,550 on Sunday.

The National Institute of Meteorology has forecast more heavy rains through Monday in Brazil's southernmost state, which borders on Argentina and Uruguay.

Governor Eduardo Leite said this week it will take nearly 19 billion reais ($3.7 billion) to rebuild Rio Grande do Sul after the floods.