Louisiana Floods: Toll Rises as Authorities Declare More Disaster Zones

While flooding receded in parts of southern Louisiana, other areas saw rising waters, and the National Weather Service issued renewed flood warnings late on Tuesday.

"We're seeing unprecedented flood levels as the waters move south," Louisiana Governor John Bel Edwards said at a news conference.

Officials said 40,000 homes have been impacted by the floods and more than 8,000 people were in shelters.

More than 20,000 have been rescued or evacuated, they said, as reported by AFP.

The Louisiana governor's office later confirmed that 11 people had died in the flooding.

Twenty parishes were declared emergency disaster areas — a designation that frees up federal money to aid with rescue operations and emergency housing, among other things.

"We're just now moving into recovery phase. We're still rescuing in the southern part of the parish," said Layton Ricks, the president of Livingston Parish — more than 75 per cent of which was affected by flooding.

There were reports of looting in areas where homes and businesses were abandoned by fleeing residents.

Many municipalities implemented evening curfews to combat the problem, and to allow rescue crews to move freely at night.

East Baton Rouge Sheriff Sid Gautreaux said 10 people had been arrested for looting since Monday afternoon.

"I felt this [the curfews] is the best way to protect our residents," he said.

Mr Edwards said there were still around 34,000 households and businesses without electricity in torrid summer heat and humidity — raising concerns of mould in waterlogged buildings.

"There are still a lot of people who are suffering," the governor said.

Rescue crews were searching for more victims, with officials uncertain about how many people remain missing.

"We are going door to door," said Baton Rouge Fire Department Chief Ed Smith, describing a search and rescue process that he estimated could take another five to seven days.