An extratropical cyclone in southern Brazil caused floods in several cities, killing at least 31 people and leaving more than 1,600 homeless, authorities said on Wednesday.

More than 60 cities have been battered by the storm since Monday, and Rio Grande do Sul governor Eduardo Leite said the death toll was the state’s highest due to a climate event.

Rescue efforts expanded further west on Wednesday with helicopters headed to the Rio Pardo Valley.

Search and rescue teams had been focusing around the Taquari Valley, about 31 miles northwest of the state capital Porto Alegre, where most of the victims and damage were recorded.

More heavy rain was expected to hit the state’s centre-south region, but possibly sparing the worst-hit areas.

Authorities maintained three flooding alerts on Wednesday, for the Jacui, Cai and Taquari rivers.

TV footage showed families on the top of their houses pleading for help as rivers overflowed their banks.

Some areas were entirely cut off after wide avenues turned into fast-moving rivers.

Mr Leite said 15 of the deaths were in one house in Mucum, a city of about 50,000 people.

Once the storm had passed, TV footage showed a goat hanging from an electrical line, an indication of how high the water had risen.

Many of the victims died from electrical shock, or were trapped in vehicles, online news site G1 reported.

The town hall at Mucum recommended that people seek supplies to meet their needs for the next 72 hours.

Rio Grande do Sul was hit by another extratropical cyclone in June, which killed 16 people and caused destruction in 40 cities, many of those around Porto Alegre.