The death toll from heavy rains in Brazil's Rio Grande do Sul state has risen to 143, up from 136 on the day before, the local civil defense government body said on Sunday, as rain continues to pour on the state.

Another 125 people remain unaccounted for in the state, where rising river levels are being reported. Weather service Metsul called the situation "extremely worrying."

On Saturday evening the government announced around 12.1 billion reais ($2.34 billion) in emergency spending to deal with the crisis that has displaced more than 538,000 people in the state, out of a population of around 10.9 million.