"We couldn't see what was happening. It was raining hard and the water was leaking into our house.
"Suddenly, we saw people in the sea and we went down to rescue them."
The mudslide also crushed three homes and a hotel on an island off the city of Angra dos Ries, burying some people in their homes on Friday.
The landslides were part of a series of mudslides and flooding triggered by heavy rains across the state of Rio de Janeiro since Wednesday, leaving dozens of people missing.
On Thursday, mudslides elsewhere in the state killed 19 people, mostly inhabitants of shantytowns in the greater Rio de Janeiro city area.
About 80 mudslides have occurred in the region and more rain is forecast for the upcoming days, officials said.
Three days of mourning have been declared locally and the city's annual celebration on January 6 has been cancelled.
Officials have warned the death toll could rise.