Floodwaters poured through a small city north of Tokyo on Thursday, stranding residents who waved for help from second floor balconies and their roofs.

As heavy rain pummeled Japan for a second straight day, the Kinugawa River broke through a flood berm, sending a tsunami-like sea of water into Joso, a city about 50 kilometers (30 miles) northeast of Japan's capital.

Rescue workers used helicopters to pluck out residents, while others waved cloths from their veranda as torrents of water around them washed away cars and knocked buildings off their foundations.

Tokyo was also drenched with rain, but the hardest-hit area was to the north in Ibaraki and Tochigi prefectures.

One woman could not be found hours after a landslide hit houses at the foot of a steep, wooded incline. Bullet train service was partially suspended.

The rain came on the heels of Tropical Storm Etau, which caused similar flooding and landslides Wednesday as it crossed central Japan.

The Fire and Disaster and Management Agency said 15 people were injured by Etau, two seriously, both elderly women who were knocked over by strong winds.