Rescue workers search for victims Sunday after last week's landslide in Nova Friburgo. (Reuters)

Anger and frustration are growing in southeastern Brazil where the confirmed death toll from last week's mudslides has surpassed 600.

Four days after the disaster, complaints are mounting about a lack of help from authorities as survivors cope with steady rains, which threaten rescue and recovery efforts.

Survivors of last Wednesday's mudslides remain stranded in remote, stricken communities cut off by impassable roads, still waiting for food, water and medication to arrive.

The death toll in mountain towns 130 kilometres north of Rio de Janeiro had risen to 598 by Saturday and grew to 610 on Sunday. There are fears it will climb sharply higher once remote areas are reached.

In the city of Nova Friburgo alone, 274 people were killed. Another 263 people died in Teresopolis, 55 in Petropolis and 18 in Sumidouro.

Fernando Perfista dug out the body of his eldest child from the mud, then looked for the 12-year-old's three missing siblings. He sheltered the boy's remains in a refrigerator to keep scavenging dogs at bay while he searched.

Helicopters airlifting wounded, not delivering food: survivors

After failing to find his other children in the Fazenda Alpina area of Teresopolis, the 31-year-old ranch hand built a gurney from scrap wood, carried his son's body down a mudslide-wrecked slope before dawn Friday and buried him in a homemade coffin.

Amauri Souza, a 38-year-old who helped Perfista carry his son's body, said a few helicopters had reached isolated areas, but "they're only taking down the wounded." He said officials were not dropping off body bags or food or water, adding that he feared the consequences if aid did not arrive soon.

"The water is rotten, but people are forced to drink it. There is no food. I had meat in my house, but it's all gone bad," Souza said.

A large part of the region is still without phone service and electricity. The slides were triggered by drenching rains that dumped 26 centimeters of precipitation in less than a day.

The head of the mortuary in Nova Friburgo says the government has ordered him to bury the bodies, even if they have not been identified.

Local and state fire departments say they have deployed 2,500 rescuers, while 225 federal policeman are in the area to maintain order.

The federal government has been trying to fly in 11 helicopters to remote areas, but has found it difficult because of the rain and low clouds.

Weary from days of steady rain, survivors and rescuers are bracing for severe thunderstorms predicted for Sunday.

With files from The Associated Press