Heavy rains and flooding in the southern state of Rio Grande do Sul since last week also have left 128 people missing, authorities said. More than 230,000 have been displaced, and much of the region has been isolated by the floodwaters

More storms are expected in the state, with lightning strikes and wind gusts reaching up to 100 kilometers per hour (62 mph) in the south, according to Cátia Valente, the meteorologist in the state's situation room

Staffers of the state's civil defense agency told The Associated Press they have been struggling to persuade residents of the city of Eldorado do Sul, one of the hardest hit by the floods, to leave their homes. It is located beside Porto Alegre, near the center of the state's coastline. At least four people declined to evacuate

The civil defense agency's own urgent warning asking displaced residents not to return to flooded areas also stressed the risk of disease transmission

Army Gen. Marcelo Zucco, one of the coordinators of rescue operations, told the AP his team is working at full speed before heavy rains that are forecast to hit the Porto Alegre area this weekend. Moderate rain was falling Wednesday afternoon in the city

"We hope the next rains are not like those we saw, but there's no way to be sure there won't be trouble ahead of us," Zucco said

"At this moment we are focusing on finishing rescue operations and starting logistical support to the population. That's bringing water, medication, food and transportation for the sick to some hospital," the general added

He also said some improvement in conditions for the day helped his men finally access some areas by land

A report by the National Confederation of Municipalities estimates damages at 4.6 billion reais (USD 930 million) in nearly 80% of Rio Grande do Sul's municipalities