The Meteorological Agency issued a heavy rain emergency warning for the island town of Yoron in the southwestern prefecture of Kagoshima on Saturday.
Under the warning issued at 2:40 a.m., the agency urged residents to immediately take measures to protect their lives.
In Kagoshima's Amami region and the northern part of the main island of Okinawa Prefecture, warm and humid air flowed in between Friday night and early Saturday, causing torrential rain, according to the agency.
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