Rescue workers search for victims of a landslide in Teresopolis, Brazil, on Wednesday. Floods and landslides devastated towns in a mountainous area near Rio de Janeiro. (Luiza Garcia/Reuters)

The death toll following mudslides north of Rio de Janeiro rose to 464 Thursday as survivors of the Brazilian disaster scrambled to reach neighbours trapped under layers of mud.

Wednesday's slides blasted through the mountainous region, destroying homes and businesses and sweeping away cars and trucks.

Roads and bridges were also washed away, making it nearly impossible for emergency vehicles to reach the area. Survivors were left to dig through the mud with shovels and bare hands.

Officials said 210 people had died in the city of Teresopolis. Witnesses described hearing a tremendous rumble as tonnes of earth above their neighbourhood slid down a sheer granite rock face there at about 3 a.m. Wednsday.

"We were like zombies, covered in mud, in the dark, digging and digging," said Geisa Carvalho, 19.

Cars sit in debris in Teresopolis, 65 kilometres north of Rio de Janeiro, on Wednesday. (Roberto Ferreira/Agencia O Dia/Associated Press)

The power was out, but by lightning flashes they could see a torrent of mud and water rushing just metres from their home — and the remnants of their neighbours' houses that were swept far down a hill.

"I don't even have the words to describe what I've seen," said Carvalho's mother, Vania Ramos, as she started on an eight-kilometre hike to the main part of her town, hoping to find food and water.

Teresopolis and surrounding communities have been hit hard by floods and landslides, local officials say.

"A lot of our friends are dead or missing. There are people we may never find."

Carvalho and Ramos said they ran out of their home moments after the mudslide and joined neighbours in their Caleme neighbourhood as they dug with bare hands and sticks in efforts to find neighbours.

They quickly located a family of four buried under the rubble of their home — and said another neighbour's two-month-old baby was washed away in his crib and has yet to be found.

Nearly all the homes in their neighbourhood were swept to the bottom of a hill and turned inside out. Tangles of plumbing were wrapped in trees, children's' clothing littered the earth, massive trees were tossed about like toothpicks. A river of water and mud flowed through the streets as a light rain continued to fall.

Only a few rescuers had managed by Thursday to hike to their neighbourhood and they only had shovels and machetes to help them look for survivors. Residents said they had no food, water or medication, and many made the long walk to the main area of Teresopolis to get help.

Annual occurrence

Such disasters hit Brazil annually in its rainy summer season and unduly punish the poor, who often live in rickety shacks perched perilously on steep hillsides with little or no foundations.

Officials said the area hit by slides had seen 26 centimetres of rain fall in less than 24 hours. More rain, possibly heavy at times, is forecast through the weekend.

Residents cross a mud-filled street after a landslide in Teresopolis. (Luiza Garcia/Reuters)

Survivors across the region were seen wading through waist-high water, carrying what belongings they could, trying to reach higher ground. Many tried desperately to find relatives, though phone service was out in the region and many people were still missing hours after the rain stopped.

"There are so many disappeared — and so many that will probably never be found," said Angela Marina de Carvalho Silva, a resident of Teresopolis who feared she may have lost 15 relatives, including five nieces and nephews.

"There was nothing we could do. It was hell," she said in a telephone interview.

Carvalho Silva took refuge in a neighbour's house on high ground with her husband and daughter, and watched the torrential rain carry away cars, tree branches and animals and rip apart the homes of friends and family.

"It's over. There's nothing. The water came down and swept everything away," said her husband, Sidney Silva.

Hopes dimming

President Dilma Rousseff flew by helicopter over the region Thursday. The nation's Health Ministry said it was sending 6.4 tonnes of medications to the area, enough to treat 45,000 people for a month, it said in a statement.

The mayor of Teresopolis, Jorge Mario Sedlacek, decreed a state of emergency, calling the calamity "the worst to hit the town." About 800 search and rescue workers from the state's civil defence department and firefighters were digging for survivors, but hopes were dimming.

Deadly flooding and slides hit neighbouring states in recent days as well.

Heavy rainfall caused havoc in Minas Gerais state north of Rio, where 16 people died in the past month and dozens of communities are in a state of emergency.

In Sao Paulo, flooding has paralyzed main thoroughfares in the capital city since Sunday and 21 people died in collapsed homes, mudslides and flooding throughout the state.

With files from CBC News