RIO DE JANEIRO, Dec. 25 -- The death toll from heavy rain-caused disasters in Brazil's southeastern state of Espiritu Santo rose to 18 after authorities confirmed the death of the latest victim, the Regional Civil Defense office said Wednesday.

The number of residents forced to evacuate, meanwhile, was adjusted from the nearly 50,000 reported Tuesday to 48,000, the agency said in a press release.

The death toll may still rise as communication with many towns has been cut off by the rains and flooding, which have also interrupted clean water and electricity service, the agency said.

Of the 78 cities in Espiritu Santo state, 50 have been declared in a state of emergency, due to rains that started last week.

Reanto Casagrande, governor of Espiritu Santo, said the downpours represented the worst weather disaster in the history of the state.

"We will have to reconstruct the whole state," Casagrande told reporters.

In some places, rescue work can only be carried out by helicopter, as flood waters have blocked road access.

On a tour of the affected region Tuesday, Brazil's President Dilma Rousseff said she had never seen "so much water" and that the priority now was to save those at risk to prevent more deaths.