Disaster response authorities in southern Brazil say the death toll from severe floods has risen to 145.

Authorities in the state of Rio Grande do Sul also say 132 people are unaccounted for as of Sunday.

The state has been hit by heavy rain since late April.

Local media are reporting that some athletes from the state have given up on their quest to secure a place in the Paris Olympics to focus on helping those affected.

Rowers Evaldo Becker and Piedro Tuchtenhagen were due to take part in a double sculls qualifying round for the Games in Switzerland from May 19. But the pair has decided to stay in the state and work as volunteers.

Tuchtenhagen said competing in the Olympics was his dream but when he saw the situation residents are facing, he set his mind on supporting them.

Heavy rain is continuing in southern Brazil. Officials are warning of the possibility of more floods.