Local authorities have confirmed that at least 18 people have died and 14 are missing in Kumamoto and Kagoshima prefectures, with pictures of the worst affected areas showing houses completely destroyed by the force of the floodwaters.
The Japanese Meteorological Agency on Saturday issued a warning about unprecedented rainfall, calling on residents of Kyushu to “exercise extreme caution”. At least 270,000 people had to evacuate in four prefectures on the island.
The village of Kuma in Kumamoto recorded a record 83.5 miles of precipitation in one hour on Saturday morning, according to the weather agency, while the city of Kanoya in Kagoshima had 109.5 mm in one hour on Monday, its highest level never reached.
A heavy rain warning remains in place Monday for parts of Kumamoto and Kagoshima, and further flooding is expected.
Speaking at a press conference on Monday, Cabinet chief secretary Yoshihide Suga said more than 800 people have been rescued so far by the emergency services.
According to the Japanese Fire and Disaster Management Agency, thousands of households have been isolated and 20,000 firefighters are currently on the ground trying to reach them. Authorities were using 28 helicopters, four planes and two research vessels to probe the area on Monday.
Officials told CNN they are still collecting information on the death toll and expect to update their numbers in the coming days.