A cyclone has left at least eleven people dead in Brazil's southern state of Rio Grande do Sul, authorities said on Saturday.

"According to the state branch of Protection and Civil Defense, 11 people died from the effects of the cyclone," the government of Rio Grande do Sul state said in a statement.

Governor Eduardo Leite said that a 4-month-old baby was among those killed.

Helicopter searches are being conducted for 20 people who have been reported missing amid torrential rain caused by the storm.

Deaths were reported in seven cities, the governor said.

"This first moment, since Thursday night until now, is especially to protect human lives, support and rescue people," Leite told the media at a briefing on Saturday with other authorities.

Thousands evacuated

The town of Caraa, which is home to more than 8,000 people, was among the worst hit with heavy flooding being reported.

"The situation in Caraa deeply worries us. It is essential that we can, in an organized way, quickly map the main affected areas and identify the people who need support," Leite said.

Nearly 3,000 people have been evacuated from their homes in a total of 40 municipalities of Rio Grande do Sul, according to the Civil Defense, LUSA news agency reported.

Several roads in the state continue to be blocked and flights to Rio Grande do Sul's main cities were canceled all through Friday.

Power outages were reported across the state.

Meanwhile, Maquine, a municipality on the eastern coast, had received around a foot of rain.

Many residents from the affected areas have taken refuge in outdoor sports facilities in their towns.

Authorities have also issued landslide warnings in several areas.