Tokyo, Aug. 14 -- Four people have died, and another remains unresponsive after torrential rain severely battered eastern Japan from Thursday into early Friday, triggering widespread flooding and high-level emergency alerts across the region, Kyodo News reported.

According to reports by Kyodo News, the Japan Meteorological Agency briefly issued a Level 5 warning, the highest disaster alert level on its scale, covering more than one-third of the municipalities in Chiba Prefecture near Tokyo. All emergency warnings were downgraded Friday morning.

Severe road flooding inundated communities across Chiba Prefecture, prompting municipal authorities in cities including Chiba and Ichikawa to urge residents to take immediate safety measures. The...