Record rainfall has deluged southwestern Japan since Thursday, causing widespread flash flooding, landslides, burst riverbanks and travel chaos.
Japanese public broadcaster NHK reported about 364 millimeters (14.3 inches) of rain fell between 5 a.m. and 7 a.m.in the city of Uwajima - approximately 1.5 times the average monthly rainfall for July.
"I was in a auto and massive floods of water gushed towards me from the front and back and then engulfed the road".
"There are still many people missing and others in need of help", the prime minister told reporters on Sunday.
Yoshihide Suga, Japanese government spokesman, said the whereabouts of 92 people were unknown, mostly in the southern area of Hiroshima prefecture.
A total of 8.63 million people in 23 prefectures from the Kyushu to Hokuriku regions have been ordered to evacuate.
Elsewhere, work crews tried to clear multiple small landslides that coated roads, rendering them virtually impassable. Military paddle boats and helicopters were bringing people to dry land.
Many severe warnings have been lifted as the rains ease, aiding rescue efforts.
The rain began late last week as the remnants of a typhoon fed into a seasonal rainy front, with humid, warm air pouring in from the Pacific making it still more active-a pattern similar to one that set off flooding in southwestern Japan exactly a year ago that killed dozens.
Authorities have warned that landslides could strike even if the rainfall diminishes.
"I am most grateful to rescuers", said 79-year-old Shigeyuki Asano, a patient who spent a night without electricity or water.
Also in Ehime, two primary schoolgirls and their mother who got sucked into a mudslide were pulled out but could not be revived.
Japanese self-defence forces personnel remove stones scattered by debris flow in Hiroshima on July 8, 2018.
Okayama prefecture, south of Hiroshima, said in a statement that five people had died, seven were missing and 11 were injured, at least one of them seriously.
A woman in her 70s or 80s was reportedly found dead inside a drainage facility in central Japan, local police reported, with a number of people remaining unaccounted for, including a man in Kochi Prefecture whose milk deliver auto may have been washed away by a river.
On the ground floor of their formerly well-decorated home, the powerful flood water had ripped away the outer layer of the walls, exposing the elaborate bamboo mesh inside.
Information about the people at the municipal shelters is still sparse, while social media buzzes with photos and video of the disaster-stricken country.