People play in a flooded street in the center of the city of Franco da Rocha (Photo: Reuters)
Devastating mudslides and floods swept away entire neighbourhoods in mountains near Rio de Janeiro, killing at least 335 people as rescue workers searched frantically for survivors Thursday.
Villages and homes in the three municipalities north of Rio were flattened by rivers of mud and tumbling rocks spilling from the mountains, GloboNews television said.
"It's a huge catastrophe, a major disaster," Jorge Mario Sedlacek, the mayor of the worst-hit town of Teresopolis said. At least 146 people have been killed in the town, 100 kilometres (62 miles) from Rio.
Other officials said the disaster was the worst ever to befall the Serrana, a soaring, lush area that used to be a getaway for 19th-century Brazilian nobility and which is now a tourist spot, especially for Rio residents during the current southern hemisphere summer.
In Nova Friburgo, 140 kilometers north of Rio, the number of victims rose to 155, while 34 were killed in Petropolis, according to GloboNews.
At least three firemen were killed when they were engulfed in tons of mud as they tried to rescue victims.
The death toll could rise in the coming hours, a spokesman for the Teresopolis municipality said. "There are villages in the interior which we haven't yet reached," he said.
Officials in Teresopolis said 2,200 people have either lost or had to abandon their homes.
The full extent of the devastation remained unknown because communication and access to the stricken zone was complicated by the destruction of roads and bridges, while telephone service was cut in some areas.
Authorities say they are particularly concerned over the fate of residents in the Campo Grande area of Teresopolis, where Civil Defence teams estimate 2,000 houses have been destroyed and 150 people buried, according to the G1 de Globo website.
Rescue teams were expected to arrive later Thursday.
The calamity was the first natural disaster facing Brazil's new president, Dilma Rousseff, who took power less than two weeks ago. She was scheduled to fly over the disaster zone in a helicopter later.
At least as much rainwater as the region usually sees in two or three weeks hit the Serrana before dawn on Wednesday, as residents were sleeping in their homes.
The downpour triggered mudslides and caused rivers to burst their banks, carrying away cars, homes and people.
Meteorologists blamed the extraordinary precipitation on a cold front that intensified the already heavy wet season southeastern Brazil experiences every summer.
That cold front moved through Sao Paulo early in the week before moving on to Rio de Janeiro state.
More rain was forecast in the coming days.
Rousseff's government has released 467 million dollars in emergency aid to help the rain-hit region.
The health ministry announced it was also sending seven tonnes of medicine, including antibiotics, blood pressure remedies, masks and syringes -- enough to last 45,000 people for a month.
The deadly downpour happened one year after mudslides killed more than 50 people in Angra dos Reis, another tourist area.
At least 473 people were killed in Brazil last year as a result of heavy rains, according to the Estado de Sao Paulo newspaper.