Torrential rain caused floods and triggered landslides in western Japan last week, bringing death and destruction to neighborhoods built decades ago near steep mountain slopes.
At least 176 people were killed, the government said, with dozens missing in Japan's worst weather disaster since 1982.
In Kumano, a mountainside community in Hiroshima prefecture that was hit by a landslide last week, Ken Kirioka anxiously watched rescuers toiling through mud, sand and smashed houses to find the missing, including his 76-year-old father, Katsuharu.
"He is old and has a heart condition. I prepared myself for the worst when I heard about the landslide on Friday night," he said, pointing at a pile of mud and rubble where he said his father was buried.
"He is an old-fashioned father who is hard-headed and does not talk much," Kirioka said, adding he would stay until his father was found. "It would be too bad for him if a family member were not around."
Rescuers working under a scorching sun and oppressive humidity combed through heaps of wood and other debris and thickly caked mud in a search for bodies, helped by sniffer dogs. In some cases only the foundation of homes remained as they cut through debris with chain saws.
With temperatures of 33 C or higher in the devastated areas in Okayama and Hiroshima prefectures, attention turned to preventing heat-stroke among rescue workers and in evacuation centers where thousands of people have sought shelter.
People sat on thin mats on a gymnasium floor in one center, plastic bags of belongings piled around them and bedding folded off to the side. Portable fans turned slowly as children cried.
Abe, who cancelled an overseas trip to deal with the disaster, was criticized after a photograph posted on Twitter showed Abe and his defence minister at a party with lawmakers just as the rains intensified.