Firefighters react during a mass in tribute to the victims of landslide in Nova Friburgo January 18, 2011. [Photo/Agencies]

RIO DE JANEIRO - At least 207 people are still missing after Brazil's worst landslides in decades, authorities said on Wednesday, as the death toll from the disaster in a scenic mountain region rose steadily to 727.

The list of missing people released by the Rio de Janeiro state prosecutor's office - the first official estimate of the number of missing since the catastrophe struck a week ago - suggests the final death toll could be close to 1,000.

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Local officials in the worst-affected towns of Teresopolis and Nova Friburgo said the number of missing was at least 300. Many of them are assumed to be buried under the avalanches of mud and water that destroyed hundreds of homes.

"There are families that were so decimated that there is no one left to confirm who's missing," said Roberto Botto, a spokesman for the Civil Defense agency in Nova Friburgo, where at least 345 people died.

The death toll has been rising daily as rescuers reach isolated areas and dig out more bodies from the wreckage of neighborhoods that were virtually wiped out by the landslides and floods following torrential rain in southeast Brazil.

Army helicopters have been running missions to remote areas to pick up survivors and help them dig corpses from their ruined houses. Hundreds of people are believed to still be in areas at risk of fresh mudslides. Some of them are cut off from help by smashed roads and bridges while others refuse to leave for fear their houses will be raided by looters.

The floods and mudslides hit with such force that the geography of the region has changed profoundly, officials said.

"Streams turned into wide, deep rivers. There is a huge geographical change; it's as if towns were completely re-founded," said Icaro Moreno, president of EMOP, a government public works firm.

"People in these mountainside areas aren't as secure as they used to think."

The federal government vowed this week to set up a national early warning system that could alert communities to approaching natural dangers.

Populist politics and lack of urban planning across much of Brazil has allowed the construction of whole neighborhoods in areas with high risk of flooding and mudslides.

Rescue workers stand next to a dead body found after a landslide in Nova Friburgo January 17, 2011. [Photo/Agencies]