More than 70 000 personnel were involved in ongoing search and rescue missions for the 60 or more people still unaccounted for in the areas affected by the deluge Xinhua news agency reported.
These include the hardest-hit regions of Hiroshima Okayama and Ehime prefectures.
The Fire and Disaster Management Agency said that as of early Thursday morning 6 700 people remained in emergency evacuation shelters.
As some of the shelters were without air-conditioning the Health Ministry warned of heat-related illnesses. Te weather agency said daytime temperatures could reach 35 degrees Celsius in the coming week.
The ministry specifically warned about the possibility of food poisoning as in the past people fell ill in such shelters after consuming food that had been left out in the heat for too long amid lack of refrigerators.
Around 240 000 homes were cut off from water in western Japan and transportation systems were also severely disrupted.
The Transport Ministry West Japan Railway Co. and local operators of the 27 lines in the affected areas reported damage at over 100 locations and will be unable to restart services within the next few days.
--IANS soni/mr
