Severe floods in the southern Mexican state of Tabasco were continuing to cause havoc and devastation on Saturday.

People evacuate a flooded area in Villahermosa, Mexico, Saturday.
(Eduardo Verdugo/Associated Press)

Officials estimate as many as 800,000 people are homeless after a week of heavy rain swamped the Gulf Coast state.

Rivers burst their banks late Thursday, submerging about 70 per cent of the low-lying state and 80 per cent of the capital, Villahermosa.

Thousands of people remained stranded on rooftops Saturday, awaiting rescue by army boats and helicopters, officials said.

At least one death was reported on Friday and nearly all services, including drinking water and public transportation, were shut down after the state's worst flooding in 50 years.

A neighborhood sits under floodwaters in Villahermosa on Friday.
(America Rocio/Associated Press)

The flood has affected almost half of the roughly two million people who live in Tabasco, their homes flooded, damaged or cut off by high water.

"We had floods before but less big than this one. This is super big, enormous, we lost everything, everything," said one woman in Villahermosa, home to 750,000 people.

Thousands have fled to the neighboring states of Chiapas and Veracruz seeking refuge, but many others have stayed in their neighbourhoods to prevent looting.

On Saturday, some people received what they thought was the best news in days as waters in the overflowing rivers finally began to recede a bit for the first time.

However, although the water levels have dropped, forecasters have predicted more rain in the coming days.

With files from the Associated Press