At least 100 people are thought to have died after record rainfall caused flooding and landslides in western Japan, a government spokesman says.
Dozens more are reported to be missing and electricity supplies have been hit.
Since Thursday, parts of western Japan have received three times the usual rainfall for the whole of July. Two million people have been ordered to evacuate as rivers burst their banks.
"We've never experienced this kind of rain before," a weather official said.
Rescuers restarted their search through the mud for any survivors or the bodies of those killed on Monday morning.
An official in Okayama prefecture told AFP news agency that water levels were gradually receding and that emergency teams may be able to access the worst-hit areas on foot.
The heavy rains began with a typhoon last week that was followed by days of record-breaking torrential rain.
In the town of Motoyama, on Shikoku island, 583mm (23in) of rain fell between Friday morning and Saturday morning.
Many buildings have collapsed and vast areas have been covered in debris and thick mud.
Kosuke Kiyohara, 38, told AFP news agency that some of his family members, including his sister, are missing. His house in the town of Kumano was destroyed by a huge landslide.
"I have asked my family to prepare for the worst," he said. "I haven't been able to reach her phone since Friday night. I wish she could have fled sooner."