More than 20,000 people were ordered to evacuate in parts of central and northeastern Japan on Friday as heavy rain sparked flooding.

The Meteorological Agency also warned of landslides and flooding in other areas as a front bringing heavy rain was expected to move south toward the country's eastern and western regions through Saturday.

An evacuation order was issued for 7,965 people in the city of Nanao, in Ishikawa Prefecture, as the Kumaki River overflowed, while the town of Hodatsushimizu, which is also in the prefecture, ordered 13,337 residents to evacuate.

In Yamagata Prefecture, a landslide blocked a road in the village of Tozawa, temporarily trapping five people. Yamagata's Mogamioguni River also flooded causing a suspension bridge to collapse.

The torrential rains also disrupted railway operations. Shinkansen services between Yamagata and Shinjo stations were suspended together with Thunderbird and Shirasagi limited express trains to and from Kanazawa Station in Ishikawa Prefecture, according to the respective railway operators.

On Friday morning 77 millimeters of rain was recorded in a single hour in the city of Wajima, Ishikawa Prefecture, and 56 mm in the town of Kaneyama, in Yamagata Prefecture, the Meteorological Agency said.

With the storm front extending from the Sea of Japan to the Tohoku region, damp and warm air flowed over the country creating unstable atmospheric conditions, the Meteorological Agency said.

In the 24-hour period through Saturday morning, up to 180 mm of rain is expected in the northeastern and central regions, while western Japan is forecast to receive up to 120 mm.