An aerial photograph shows a break in highway BR 356 that was washed away in Campos
An aerial photograph shows a break in highway BR 356 that was washed away after several days of heavy rains swelled the Muriae River in Campos, 230 km (142 miles) northeast of Rio de Janeiro, January 5, 2012. Civil Defense officials said the 4,000 residents of the town are being evacuated, and they expect the flooding to continue for three to four months. REUTERS

Brazilian authorities on Thursday said they are trying to evacuate 20,000 people in the state of Rio de Janeiro after a dam burst following days of torrential rain.

Flooding on the Muriae River caused a dike to break, sending water through the town of Campos do Goytacazes, 275 kilometers (170 miles) outside Rio de Janeiro; it created a 20-meter-wide crater in the highway, according to the Municipal Civil Defense. More than 4,000 people had to be evacuated.

Sixty-six towns and cities in Minas Gerais have declared a state of emergency, with many other areas in the southeast of the country on red alert, The Telegraph reported.

Eight people have died and at least 10,000 displaced after days of heavy rain, which raises the risk of mudslides in addition to the flooding. Typically, rain falls at an average of 4.9 inches during the whole month of January, but many locations are reporting this amount of rain in only 24 hours.

Brazil's Intergration Minister Fernando Bezerra said resources will be available for Rio's officials to handle the worst affected regions.

I hope Rio's civil defense will continue their efforts, especially in the most critical regions so that we may, in a joint effort with all institutions involved, avoid the loss of human lives and reduce material losses, he said.