Japan on Friday issued high risk alerts in its southwestern regions, urging residents to prepare and evacuate. Highest risk alerts were issued in the western prefecture of Hiroshima, accompanied by warnings of imminent risk of floods and other disasters amid unprecedented rains. The Japan Meteorological Agency issued the warning, urging residents to prepare and act early. The agency added in a statement that the rain front could stay over the country for about a week. Television footage on NHK public broadcaster showed rivers swollen with muddy water gushing down, almost overflowing, in Hiroshima. On Thursday, hundreds of thousands of residents of Nagasaki and other parts of Kyushu island in southwest Japan were asked to evacuate to avoid floods and the risk of landslides caused by torrential rain. In the city of Unzen in Nagasaki prefecture, rain triggered a mudslide on Friday that hit two houses with four residents. One was presumed dead when …