At least three people are missing and thousands have been ordered to evacuate after torrential rains pounded northern Japan, flooding roads and causing rivers to burst their banks.
More than 500mm of rain had fallen in one part of Niigata prefecture in the 24 hours to 1pm local time (2pm AEST) on Thursday, NHK public television said, prompting authorities to issue the highest level of disaster warnings in some areas.
Bridges were cut and roads flooded, television footage showed.
Service along one portion of a Shinkansen bullet train line was suspended.
Roughly 500,000 people were ordered to evacuate in Niigata, Ishikawa and Yamagata prefectures, the Fire and Disaster Management Agency said, but there were no immediate reports of fatalities.
Though the affected areas are largely rural, they are also home to a number of factories.
Major chipmaker Renesas Electronics temporarily suspended operations at its factory in Yamagata after local authorities issued a warning over heavy rains on Wednesday evening. They said on Thursday operations were mostly back to normal.
Technoflex said it was suspending production at a factory in Murakami due to a power outage and flooding.