Eight people died and at least 13 were missing after rain-sodden hills in the outskirts of Hiroshima gave way early Wednesday in at least five landslides.
Video footage from the national broadcaster NHK showed suburban homes in the western Japanese city surrounded by streams of mud and debris, and residents picking their way over piles of rocks and dirt.
Rescue workers suspended by ropes from police helicopters were pulling victims from the rubble as they searched homes stranded amid piles of lumber from crushed houses.
Authorities issued warnings for possible further landslides and flooding due to unstable weather conditions.
Landslides are a constant risk in mountainous, crowded Japan, where many homes are built on or near steep slopes. Torrential rains in the early morning apparently caused slopes to collapse.