At least eight people have died and 21 are missing after flooding caused by heavy rainfall in the southern Brazilian state of Rio Grande do Sul, authorities said.
About 1.400 people were evacuated in more than 100 municipalities, most of whom were transferred to emergency accommodation, the Civil Defense announced.
"We continue to work intensively to find the missing and ensure security in the risk areas," said state governor Eduardo Leite and warned that additional rainfall is expected.
Due to floods, landslides and collapsed bridges and roads, some parts of the country cannot be reached or help can be delivered.
The Civil Defense announced that since yesterday it has been focusing on rescuing families who were trapped in their homes, often finding refuge on the roofs of residential buildings.
Brazilian President Luiz Inácio Lula da Silva ordered aid to be sent, attributing the disaster to "climate change affecting the planet".
The armed forces are also engaged in rescuing people in hard-to-reach areas.
In the state of Rio Grande do Sul, about 130.000 people are without drinking water, and telephone and Internet connections are down in at least 60 municipalities.
Weather forecasts still predict up to 300 millimeters of new rain in some areas where rivers have already swelled.
In late March, heavy rains in southeastern Brazil killed 25 people in the states of Rio de Janeiro and Espirito Santo. The south and southeast of Brazil are currently affected by the arrival of a cold front after an extreme heat wave.
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