A city official said late yesterday that 170 patients and staff had been evacuated, while public broadcaster NHK later said about 80 people were still stranded.
TV footage showed a residential area in Okayama, in south-west Japan, with brown water spreading like a huge lake.
Kyodo news service reported another death in a landslide in Hiroshima, which set off a fire, while the body of a child was found in a flooded area.
Prime Minister Shinzo Abe called the situation "extremely serious" and ordered his government to "make an all-out effort" to rescue victims.
As of Saturday, at least 67 people were missing with the majority in Hiroshima, 47, while others were unaccounted for in Ehime and Okayama Prefecture.
"I went to my father's family home but it was hopeless", a man in submerged Kurashiki City said, according to the BBC. "I was just able to escape, but I was terrified", 62-year-old Yuzo Hori told the Mainichi Shimbun daily in Hiroshima.
Portugal's Cristiano Ronaldo can't be stopped by one player - Uruguay coach
Penalty shootouts excluded, Portugal have lost only one of their last 17 games at major tournaments (W8 D8), a 4-0 defeat against Germany at Brazil 2014.
At least 70 people have died and dozens others remain missing on Sunday after torrential rains triggered massive flooding and landslides in western Japan.
At 5:50 a.m. on July 8, the Japan Meteorological Agency issued an "emergency warning against heavy rain" to Kochi and Ehime prefectures, meaning that serious damage could result from a deluge that might occur only once in decades.
Though the rains began last week when a typhoon made landfall, the worst downpours hit from Thursday, when a construction worker was swept away by floodwaters in western Japan.
Several major manufacturers, including carmakers Daihatsu and Mitsubishi, suspended operations at plants in the affected areas. Roads were also damaged and flooded everywhere and many railway sections remain disrupted.
"I've lived here for 40 years. I have never seen anything like this", he said, standing in shock before the house where he and his wife raised their three daughters, all now adults.
Amid reports of dead and missing, some 1.2 million Japanese were advised to evacuate their homes as monsoon downpours continued to pound the island nation Friday.
Nearly 2 million people were still subject to evacuation orders, while tens of thousands of rescue workers battled mud, water and rubble to search for survivors stranded in their homes. Many of those who defied the instructions, however, have found themselves caught in flash floods and landslides.