Hundreds of thousands of people are fleeing some of the worst floods to have hit Mexican in more than 50 years.
About a million people have been hit by the floods in the southern state of Tabasco, with 800,000 left homeless and thousands more trapped in their homes.
Helicopters are being used to airlift people to safety from their rooftops.
The Mexican president, Felipe Calderon, said the flooding was "one of the worst in the country's recent history" and promised support for those affected.
He said the entire air force was involved in getting emergency supplies to the region.
The rising flood waters have left about 80% of Tabasco under water
Emergency shelters have been set up on high ground in Tabasco and the neighbouring states of Campeche and Veracruz.
The capital, Villahermosa, and many other towns in the state have been turned into brown lakes with only treetops and roofs visible.
So far, one person is known to have died in the floods.