Some 75,000 people were ordered to evacuate in western Japan Saturday as record heavy rain triggered floods and landslides, leaving scores stranded and 13 missing, according to local media and officials.
The nation's weather agency issued the highest emergency level of heavy rain warnings to Kumamoto and Kagoshima on Kyushu island.
Television footage showed vehicles swamped at car parks near a flooding river, while several bridges were reportedly washed away.
Rescuers were searching for three people in Kumamoto after a landslide buried their house, public broadcaster NHK said.
"We have issued evacuation orders after record heavy rain," said Toshiaki Mizukami, an official of Kumamoto prefecture.
"We strongly urge people to take action to protect their lives as it's still raining quite heavily," he told AFP.
Kyodo News said 75,000 residents in Kumamoto and Kagoshima were ordered to evacuate their homes, with nearly 100 people reportedly stranded.
Local authorities have asked troops to join rescue operations, NHK said.
Some train services, including Shinkansen bullet train operations, have been suspended in the region.
Japan is currently in its rainy season, which often causes floods and landslides and prompts local authorities to issue evacuation orders.
No casualties or injuries have so far been reported.