Japanese authorities told tens of thousands of people to evacuate the quake-hit region of Ishikawa on Saturday as heavy rain lifted river levels, raising flooding fears.

Three rivers in the region were overflowing into nearby communities, a local official told AFP, adding that authorities were assessing damage to buildings and infrastructure.

Japan's Meteorological Agency said it issued its highest level warning for Ishikawa, cautioning of a "life-threatening situation."

The cities of Wajima and Suzu ordered about 30,000 residents to evacuate, local officials said.

Public broadcaster NHK aired footage showing an entire street in Wajima submerged under water.

The cities are among the areas hardest hit by a huge New Year's Day earthquake that killed at least 236 people in central Japan.

The region is still reeling from the magnitude-7.5 earthquake that toppled buildings, ripped up roads and sparked a major fire.

Japan has seen heavy rain of unprecedented levels in parts of the country in recent years, with floods and landslides sometimes causing casualties.