Sharjah24 - WAM: Heavy rains battering Brazil's southernmost state of Rio Grande do Sul have killed 39 people, local authorities said, and the death toll is expected to rise as dozens still have not been accounted for.

Rio Grande do Sul's civil defense authority said 68 people were still missing and at least 24,000 had been displaced as the storms affected more than half of the 497 cities in the state, which borders Uruguay and Argentina.

"These numbers can still materially change over the following days as we gain access to more regions", Rio Grande do Sul Governor Eduardo Leite told reporters.

In several towns, streets essentially turned into rivers, with roads and bridges destroyed. The storm also triggered landslides and the partial collapse of a dam structure at a small hydroelectric power plant.

A second dam in the city of Bento Goncalves is also at risk of collapsing, authorities said, ordering people who live nearby to evacuate.

In Porto Alegre, the capital of Rio Grande do Sul, the Guaiba river broke its banks, and flooded streets blocked access to the city's historic central neighborhoods.

The state is at a geographical meeting point between tropical and polar atmospheres, which has created a weather pattern with periods of intense rains and others of drought.

Local scientists believe the pattern has been intensifying due to climate change.