Over 5,000 people have been evacuated in Mexico's southern state of Tabasco as torrential rains caused two rivers to overflow their banks.

'The situation is very critical,' Tabasco state Governor Andres Granier said Saturday.

Three years ago, in 2007, the state had seen heavy flooding that displaced around one million people.

The evacuation Saturday was being conducted by the army and navy in the face of rising water levels in the Carrizal and Samaria rivers.

The civil protection office has estimated that in the coming days the number of people to be evacuated could reach 150,000.

State Health Secretary Luis Felipe Graham said the priority would be to avoid illnesses being spread by the floods.

Many people have started complaining about skin problems. 'We don't have skin creams and we're getting pimples,' said Maria Gaspar Agustin, a 60-year-old resident of Villahermosa town.

Very few locals in Villahermosa have agreed to leave their homes and only 2,000 people are staying in the shelters set up by the authorities. In some neighbourhoods, people were living on rooftops.

'We've spent a week surrounded by water but I don't want to leave because I'm afraid they'll rob us,' said Maria Dolores Garcia, a resident of Miguel Hidalgo area.

The education secretary of Tabasco state, Rosa Beatriz Luque, said 8,000 students are missing classes because schools have been flooded in 42 towns in the state.