(Updates death toll, missing in paragraph 6)
By Raymond Colitt
BRASILIA, Nov 26 (Reuters) - Brazil sent hundreds of state and federal police officers on Wednesday to quell looting by homeless and hungry landslide victims facing the threat of disease after heavy flooding that authorities say killed more than 100 people and displaced 54,000.
Rescue workers shoveled through massive mudslides that buried homes and cars and ferried stranded survivors to safety in rubber dinghies, as the disaster prompted President Luiz Inacio Lula da Silva to visit the region on Wednesday.
Lula authorized nearly 2 billion reais ($881 million) in emergency relief funds, his office said in a statement, after residents complained that food aid had failed to arrive.
Of that amount, 730 million reais will go to help rebuild damaged hospitals, roads and railways in the region.
Six areas in southern Santa Catarina state declared a state of emergency, some of them wealthy districts, and as many as 100,000 people are still largely trapped after landslides and raging rivers washed out roads and cut power.
The Civil Defense agency said the official death toll rose to 99 but estimated it was more than 100. Nineteen people were still missing.
In the cities of Blumenau and Itajai, among the worst hit by the floods, people ransacked supermarkets and grocery stores during the night in search of food, local officials said.
"Many haven't had food or water in four or more days. They're hungry," Maj. Sergio Murillo de Mello, commander of the Itajai fire department, told Reuters.
"We desperately need those food baskets that were promised," he said.
Television footage of the region showed houses and cars buried under mudslides, while trees and household items drifted through flooded streets.
A handful of people were arrested in Blumenau for looting.
More than 200 police officers and at least 50 agents of the National Security Force were arriving from The state capital, Florianopolis, to help prevent further looting in the flooded cities, a spokesman for the local police told Reuters.
The Itajai river, which rose by more than eight yards (meters) and flooded nearly 90 percent of the city's houses, began to recede on Wednesday, local authorities said.
But around a quarter of the houses remained flooded by more than a yard (meter) of water, they said. Meteorologists forecast more rain in the region on Thursday.
The spread of disease was now a major concern, said de Mello. "Sewage water spilled into the streets and with people homeless and walking barefoot, it's a big concern," Mello said.
Minister of Health Jose Temporao, in the region to help coordinate rescue efforts, announced the shipment of 17 tonnes of medical supplies, including antidotes for snake bites.
The army will set up a regional field hospital, he said.
The Port of Itajai, where docks were seriously damaged, has shut down. Contraband goods confiscated by customs had washed out to sea as a warehouse collapsed.
"We haven't seen a ship here since Friday. We're closed," said Itajai port spokeswoman Patricia de Barcelos.
Food processor Sadia SDIA4.SA (SDA.N), one of several large companies that use the port, said its exports did not suffer significantly and it is shipping from other ports.
Repairs could take several months and some ships were being rerouted to the port of Santos, around 437 miles (700 km) northeast of Itajai, de Barcelos said.
Repairs of a pipeline that carries natural gas from Bolivia to Brazil would take up to 21 days, the operator said, leaving hundreds of manufacturers in Santa Catarina and neighboring Rio Grande do Sul state cut off.
Steelmaker Gerdau (GGBR4.SA) (GGB.N) said it had to reduce production and was looking for alternative energy supplies. It gave no further details. (Additional reporting by Alice Assuncao, Pedro Fonseca, and Eduardo Simoes; editing by Philip Barbara)