The state of Santa Catarina declared an emergency as rescuers used helicopters and motorboats to help those displaced by the floods after days of torrential rain.
"Santa Catarina is facing its worst weather tragedy," state Gov. Luis Henrique Silveira told reporters.
Brazilian President Luiz Inacio Lula da Silva called Silveira and told him the federal government stood ready to provide medicine and other supplies, the state said on its Web site.
The state government said the floods and mudslides had affected 1.5 million people, leaving about 150,000 people without electricity and five towns out of the 60 affected completely cut off by flood waters.
The death toll was likely to rise as several people were missing, state officials said.
The floods also shut down a branch of a pipeline carrying natural gas from Bolivia to Brazil, cutting off supplies to Santa Catarina and neighboring Rio Grande do Sul state, the company that operates the line said.
Brazilian newspapers showed photographs of streets submerged by the waist-high flood waters in the state, which is one of Brazil's wealthiest and known for its large number of descendants of German and Italian immigrants.
Transport in the state was paralyzed as roads were cut off by the flooding and landslides. Television footage showed hillsides breaking away and sliding into rivers of mud. A lane of one main road collapsed after its earth foundations crumbled.
Folha de Sao Paulo newspaper said at least one town was rationing water because of purification problems.
Thirteen people died after being buried by landslides in the town of Blumenau, where officials declared a state of emergency late on Sunday and warned that more mudslides were possible. Six more died in the town of Jaragua do Sul.
"The big challenge on Monday will be supplying the shelters with medicines and food," Blumenau Mayor Joao Paulo Kleinubing said, according to the Civil Defense Agency's Web site.
The first deaths were reported on Saturday after two days of heavy downpours and weeks of steady rain. Forecasters said the rain was expected to ease in the coming days.
The Latin American country is in spring season when rains in the southern part of the country are at their heaviest, ending months of usually dry winter weather.
(Reporting by Pedro Fonseca and Peter Murphy; writing by Stuart Grudgings; Editing by Cynthia Osterman)
- Reuters - Thomson Reuters Foundation
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