Military helicopters have plucked residents from the top floors of their homes after raging floodwaters poured in and inundated a wide swath of a city north of Tokyo.

As heavy rain pummelled Japan for a second straight day, the Kinugawa River broke through a flood berm on Thursday, sending a tsunami-like wall of water into Joso, about 50km northeast of Japan's capital.

The flooding has forced more than 100,000 people from their homes, at least 17 people were injured. Two people were missing.

A 63-year-old woman was missing in a landslide that hit her home while a man in his 70s in Joso was feared trapped when water engulfed his home, NHK national television said.

Earlier, NHK showed aerial footage of rescuers lowered from helicopters and clambering onto second-floor balconies to reach stranded residents.

In one dramatic rescue by a military helicopter, the rescuer could be seen descending four times over about a 20-minute period to take four people up one-by-one, as a deluge of water swept around the home.

Yuko Yoshida from the Japanese Red Cross told Al Jazeera that the exact number of those in need of emergency rescue was not known because many people had evacuated before the rains came in.

"From our assumptions, the government has managed this situation well. Medical facilities are operating," Yoshida said.

Woman missing

Elsewhere in the region, one woman was missing hours after a landslide hit houses at the foot of a steep, wooded incline. Bullet train services were partially suspended.

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.

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  were elderly women knocked over by strong winds.

Al Jazeera's weather forecaster, Everton Fox, said the worst of the rains would clear within the next 12 to 18 hours, adding that by Friday the downpour will have largely stopped.

"The floods are likely to peak for some time because the run off from the higher ground will seep through for a couple of days and then we can expect a gradual improvement in the situation," Fox said.

A man carries belongings through a flooded street in Oyama, northeast of Tokyo on Thursday [Kyodo News/AP] 
The building of an open-air spa, right, that belongs to Kinugawa Plaza Hotel, falls into the rapid stream of the Kinugawa River swollen by heavy rainfall in Nikko, northeast of Tokyo [Kyodo News/AP]

Source: Al Jazeera And AP