Three dead, thousands homeless after Japan floods

Residents wait for help, sitting on the roof of their house in the flooded city of Joso, northeast of Tokyo. Photo / AP

Authorities are grappling with the aftermath of massive flooding that killed at least three people, as thousands of rescuers frantically searched a shattered community for almost two dozen still missing.

The heaviest rain in decades pounded the country following Typhoon Etau, which left a trail of destruction in its wake.

Hundreds of thousands were ordered to leave their homes and at least 22 people - including two 8-year-old children - were still unaccounted for yesterday in disaster-struck Joso city, about 60km outside Tokyo. Another person was missing in a northern prefecture.

Ryosei Akazawa, a member of Prime Minister Shinzo Abe's cabinet, acknowledged that emergency personnel still did not know the whereabouts of the missing, as fears grow that the death toll will rise.

Parts of Joso, a community of 65,000, were destroyed on Thursday when a levee on the Kinugawa river gave way, flooding 32sq km.

Jiji Press news agency reported yesterday that almost 11,000 homes had been flooded.

Dramatic aerial footage showed houses being swept away by raging torrents in scenes eerily reminiscent of the devastating tsunami that crushed Japan's northeast coast four years ago.

Desperate Joso residents waved towels from balconies trying to summon help, while military dinghies ferried dozens of people to safety, and helicopters plucked individuals from rooftops.

Hundreds of people are believed to still be trapped in buildings, after more than 600 had been rescued in Ibaraki prefecture.

About 5800 troops, police and firefighters have been sent to flooded areas where rescuers are working.

People were seen wading through waist-high water to reach shelters.

Another river in Miyagi prefecture, north of Ibaraki, burst its banks and flooded a populated area but many residents had already been evacuated, reports said.

Vehicles are submerged in front of a city hall northeast of Tokyo. Photo / AP

In Kanuma city, north of Joso, a 63-year-old woman was killed after being swallowed by landslides triggered by the heavy rain, and a 48-year-old woman was found dead in Miyagi. The third victim was a 25-year-old man helping to clear drains in the city of Nikko.

- AAP