Typhoon Mindulle brought violent winds and heavy rain on Friday to the Izu Islands and the Pacific coast of eastern Japan, disrupting air and train services.
The Japan Meteorological Agency warned that the storm, already causing flooding on some roads, would continue to batter the Pacific coast of northeastern Japan through Saturday morning.
It said the typhoon is expected to weaken into an extratropical depression east of Japan by Saturday evening.
As of 9:45 p.m. Friday, the typhoon, with an atmospheric pressure of 965 hectopascals at its center, was located 260 kilometers east of Choshi in Chiba Prefecture, traveling toward the north-northeast at a speed of around 40 kilometers per hour, according to the agency.
Japan Airlines canceled over 100 flights, mainly those leaving and arriving at Tokyo's Haneda airport, while some train schedules in the prefecture near the capital and other areas were affected.
Four people aged in their 70s to 90s sustained injuries after falling in Fujisawa and Atsugi in Kanagawa Prefecture, according to local authorities.
The Samuro River running through Isumi, Chiba Prefecture, overflowed due to the heavy rain, prompting local authorities to issue the highest level of warning for residents.
In the town of Ichinomiya in the prefecture, the roof of a junior high school was destroyed, they said.
Maximum wind speeds of 150 kph were recorded in Choshi and Miyake Island in the Izu island chain, respectively, according to the agency.
Also in Katsuura, Chiba Prefecture, rainfall of 39 millimeters per hour was registered, with downpours of more than 30 mm per hour on Kozu Island in the island chain and Izu, Shizuoka Prefecture.