Torrents of mud and water set off by heavy rains left a trail of destruction through the mountainous Serrana region near the city of Rio de Janeiro, toppling houses, buckling roads and burying entire families as they slept.

"It's like an earthquake struck some areas," said Jorge Mario, the mayor of the Teresopolis municipal area, where at least 158 people died.

"There are three or four neighborhoods that were totally destroyed in rural areas. There are hardly any houses standing there and all the roads and bridges are destroyed."

Heavy rains earlier in the week killed 13 people in Sao Paulo state, bringing the total number of deaths in southern Brazil to at least 388.

The disaster poses an early challenge for new President Dilma Rousseff, who was due to fly over the region on Thursday. Beside the immediate crisis of loss of life and property damage, it could further boost rising food prices that have been a major concern for the government.

Hillsides and riverbanks about 60 miles north of Rio, which will co-host the 2014 World Cup and host the 2016 Olympics, collapsed after the equivalent of a month's rain fell in 24 hours from Tuesday. Folha de Sao Paulo newspaper said it was the worst natural disaster to hit Brazil in four decades.

More heavy rain is forecast for the coming days, complicating rescue efforts and raising the risk of further mudslides.

Raging flood waters and rivers of mud totally submerged some houses and left cars crumpled like tin cans. More then 13,500 people were made homeless in the region, the Civil Defense agency said.

The worst-hit area was Nova Friburgo, a rural town first settled by Swiss immigrants, where the death toll was 168, according to local officials.

Mario said rescue teams had yet to reach several of the worst-hit parts of Teresopolis, including one neighborhood where media reports said that around 150 houses were destroyed.