300,000 trapped by Mexican floods

A huge military operation swung into action on Mexico's flooded gulf coast today trying to rescue more than 300,000 people cut off by rising waters.

Helicopters and boats worked continuously to remove thousands still stranded on rooftops of their homes.

With floodwaters stretching right across the state of Tabasco and food and drinking water scarce, health officials warned against cholera and other waterborne diseases.

An estimated 900,000 people had their homes flooded, damaged or cut off after a week of heavy rains caused rivers to overflow, leaving at least 70 per cent of the state under water.

At least one death was reported. Nearly all services, including drinking water and public transportation, were shut down in the state capital of Villahermosa.

Soldiers the city's historic centre last night as the waters of the Grijalva river burst through sandbags, flooding the city's bus station and open-air market.

Much of the city looked like New Orleans after Hurricane Katrina, with murky water reaching to rooftops.

Safe refuges were scarce and officials improvised, turning garages and any other dry buildings into temporary shelters.

Tabasco floods every year around this time, and many poor, low-lying neighbourhoods have grown accustomed to spending half a year with the first floor of their homes under water.

But this year has taken even flood-weary residents by surprise. "The situation is extraordinarily grave: This is one of the worst natural disasters in the history of the country," President Felipe Calderon said in a televised address.

Several Mexican banks established special accounts for donations to flood victims, many of whom lost everything, including their homes.

"Nobody can stand around with his arms crossed," Calderon said. "We can't and won't abandon our brothers and sisters in Tabasco."

The Grijalva, one of two large waterways ringing Villahermosa, has already risen more than six feet above its "critical" level and gushed into the city's centre and forecasters have predicted more rain.

The state of Chiapas, which borders Tabasco to the south, also reported severe flooding, with officials there estimating that more than 100,000 people have been affected.