Japan's weather agency warned Wednesday of the risk of further flooding, swollen rivers and mudslides across wide areas of the country as heavy rain from last week could continue unabated, having left at least 8 people dead already.

The Japan Meteorological Agency said more rain is forecast to hit areas from the western to northern parts of the country through Thursday as a stationary front is expected to move north along the Japanese archipelago.

The agency said the front is forecast to reach Hokkaido, the country's northernmost main island, on Wednesday night, after moving over the Sea of Japan. The front is expected to gradually weaken from around Thursday.

Rain-related accidents have already left eight people dead, with several others unaccounted for, as rescue workers continue to search for those still missing.

The Nagasaki prefectural government said Wednesday a woman in her 80s who was found collapsed in a drain the previous day in the southwestern city of Hioki had died as a result of the rain.

Also early Wednesday, an earthquake with magnitude of 4.2 hit the western city of Shobara, Hiroshima Prefecture, and the agency warned that even a small amount of rain or another quake could trigger mudslides in areas where the ground may have been saturated with rain from the past week.

In the 24 hours through Thursday morning, up to 200 millimeters of rainfall was forecast in southern Kyushu, up to 180 mm in the Shikoku region in western Japan, and up to 150 mm in the Tokai region in central Japan.

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