Nearly 2 million people were forced to leave their homes during heavy rains in some parts of Japan.
Many prefectures, including Fukuoka and Hiroshima, have issued the highest rain warnings.
After two homes were destroyed in a landslide in Nagasaki Prefecture, a woman died and her husband and daughter disappeared.
More than 150 soldiers, police officers, and firefighters were dispatched to support rescue operations in the region.
A local official told Agency France-Persse: “They are carefully looking for the missing residents. At the same time, if the rainfall continues, they also have to look out for more landslides.”
The western part of the country is the hardest hit, but heavy rains are expected across the country in the coming days.
Kyodo News quoted local authorities as saying that a hospital in Saga Prefecture evacuated patients to the upper floors after the nearby hexagonal river flooded and flooded buildings on Saturday.
According to the Japanese broadcaster NHK, a total of more than 1.8 million people in seven prefectures have received non-forced evacuation warnings.
Yushi Adachi of the Japan Meteorological Agency described the current rainfall as “unprecedented”.
“Maybe a disaster has already struck,” he said.
Pictures from local television showed that the street was flooded. Local media reported that the Saga and Fukuoka rivers were flooded and the water level had continued to rise.
An official from Kumamoto City, southwest Japan, said a 76-year-old man disappeared after trying to protect his fishing boat.
The flooding came weeks after heavy rains broke landslides and rivers, killing dozens of people.