Heavy rains caused an early morning mudslide Saturday near Rio de Janeiro, killing 10 people, injuring 11 and leaving at least four missing, Brazilian authorities said.

The mudslide in Niteroi, an area outside Rio's downtown, was caused by heavy downpours, Roberto Robadey, Rio's civil defense department head, told Globo TV network.

Robadey said that after two days of heavy rain "a state of alert was declared for Niteroi." He added that people were urged "to move to safer locations.''

Rescuers said the rain loosened a large boulder, which struck several homes and businesses. Rescuers continued to look for survivors and victims buried in the debris and mud.

Pastor Pedro Paulo dos Santos, who arrived to help, told the Associated Press, "(I found) a scene of desperation, of crying. ... In my case, this is the first time that I experience a thing like this... (I saw) many people trying to retrieve a person who was alive in the rubble."

Landslides and floods are common in Brazil, often affecting poor communities where shacks are built on steep, unstable hillsides.