Heavy rain is expected to hit again the northeastern region of Tohoku from Saturday afternoon through Tuesday.
Weather officials say that even a small amount of rain could heighten disaster risks in Yamagata and Akita prefectures where record rain has hit in the past few days. They are warning against overflowing rivers, flooding and landslides.
The Meteorological Agency says torrential rain in the two prefectures is due to a seasonal rain front becoming active. Rainfall during a few days reached 1.7 times the average for all of July in some places, attaining record highs since the agency started keeping statistics.
The land ministry says river banks had collapsed at seven locations in Akita Prefecture as of 2 p.m. on Friday.
River levels remain high in Yamagata Prefecture. Landslide alerts remain in place for some areas.
Rain in the Tohoku region has eased for the time being. But it is expected to intensify again from Saturday afternoon as warm and damp air is expected to flow in toward the front. Intermittent downpours are expected especially in areas along the Sea of Japan coast.
In the 24 hours through Saturday afternoon, up to 100 millimeters of rain is expected in parts of Tohoku. In the following 24-hour period through Sunday afternoon, up to 200 millimeters of rain is forecast for the Sea of Japan side and 150 millimeters on the Pacific side.
The rain so far has already damaged embankments and loosened the ground in some places. People are advised to stay on the alert.