He said some residents of the area had already left their homes, fearing that a landslide could strike, but others near to the bottom of the hill had remained thinking they would be safe.

The mudslide demolished more than 50 houses as well as churches and stores in its path, leaving a rubble-strewn gash of earth on the hillside.

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Al Jazeera's Craig Mauro reports on the race to find survivors from the deadly mudslides

Survivor Marlene Pineiro said she and her family heard a loud noise as the earth began moving and managed to jump out of a window before it collapsed.

"We ran and everything starting coming down… the kitchen, my brothers' room, the living room," she said. "But in the other room it stopped, so when that happened we opened the window… we jumped into the woods and ran away."

Some 200 mudslides have hit the Rio area since Monday, triggered by the worst rains in 40 years.

Rescuers said the chances of finding more survivors were slim because of the lack of air pockets in the mud.

"This has been total chaos for the last three days. I've never seen anything like this," helicopter pilot Marcos Goncalves Maia told Reuters news agency.

Threatened

The official death toll is 153, but could rise sharply as rescue teams continue to search through the debris in Niteroi.

Search teams say they fear dozens of bodies are buried in the mud [Reuters]

Most of the victims lived in hillside slums, known as favelas, which are usually flimsy structures built on steep hillsides that are susceptible to landslides.

More than a million people live in favelas across the Rio area.

At least 11,000 people have been forced to flee their homes and officials say thousands more houses could be threatened by further mudslides.

Brazil's federal government has sent troops to help rescue and recovery efforts and on Thursday announced a $113m emergency fund to help Rio state cope with the disaster.

The chaos caused by the rains has renewed attention on Rio's poor infrastructure and chaotic slum constructions as it prepares to host the World Cup in 2014 and the Olympics in 2016.

But city officials have rebuffed questions about why so many slums were allowed to be built on unstable land, saying the priority is finding survivors and helping to shelter those made homeless.

"This isn't the time to question why these constructions were allowed, it is the time for solidarity," Rio's Governor, Sergio Cabral, said as he inspected the disaster zone.