Warnings of heavy rain and flood in Japan's Kanto area, which includes the capital city of Tokyo, were issued Tuesday due to unstable air movements, according to the Japan Meteorological Agency.
The warnings are effective currently in prefectures of Nagano, Yamanashi, Kanagawa and Chiba, as well as most wards of Tokyo.
An estimate of 70 mm rainfall was measured at Tokyo's Chofu city at about 3 p.m. local time and the agency said heavy rain that could bring about 50 mm rainfall within an hour would be observed late the day.
About 100 households in Chiba Prefecture lost power and three people were hit by thunder, according to local reports.
The agency also warned that secondary disaster like mud slide and tornado could happen in the warned areas.