The death toll from heavy rains that have battered the Brazilian state of Bahia since November rose to 18 on Sunday, amid incessant torrents that have displaced 35,000 people, authorities said.

Bahia firefighters confirmed the death of a 60-year-old man who drowned in a river in the south of the state on Sunday.

Two people are also missing, while 19,580 have been displaced and another 16,001 forced to seek shelter, bringing the number of people driven from their homes to 35,000, the Bahia civil protection agency Sudec said.  

Another 286 people have been injured since the start of the downpours, Sudec added.

According to estimates more than 430,800 people have been impacted, and the situation has only worsened in recent days.

By Sunday afternoon, the number of municipalities in a state of emergency had risen to 72, of which 58 are in crisis due to flooding, according to Sudec.

"It's an enormous tragedy," said Governor Rui Costa, who surveyed damaged areas by plane Sunday.

"I don't remember something of this dimension in Bahia's recent history. The number of homes, streets and towns completely under water is truly terrifying."

A joint operation of federal and state emergency services has been mobilized since Saturday to rescue thousands of residents trapped by the flooding.