One person has died and seven others are missing, officials said, after "unprecedented" rains caused floods and landslides in the coastal quake-hit region of Ishikawa in northern Japan.

Japan Meteorological Agency (JMA) on Saturday issued its highest "life-threatening" alert level for the Ishikawa region, following torrential rains which are expected to last until midday on Sunday.

More than 40,000 people across four cities have been ordered to evacuate after at least a dozen rivers in the region burst their banks.

Two of the missing were carried away by strong river currents, according to Japan's public service broadcaster NHK.

Meanwhile, another four workers carrying out road repairs following a deadly New Year's Day earthquake are also unaccounted for.

More than 120mm (4.7in) of rain was recorded in Wajima on Saturday morning, NHK reported, the heaviest downpour in the region since records began.

JMA forecaster Sugimoto Satoshi told reporters: "This level of downpours has never been experienced in this region before. Residents must secure their safety immediately. The risk to their lives is imminent."

Footage aired by NHK showed an entire street in Wajima submerged underwater.

Government official Koji Yamamoto told AFP that 60 people had been working to restore a road hit by the quake in the city of Wajima, but were hit by a landslide on Saturday morning.

"I asked [contractors] to check the safety of workers... but we are still unable to contact four people," Mr Yamamoto said.

Rescue workers who had tried to gain access to the site, he said, were "blocked by landslides".

A further two people have been seriously injured, according to government officials.

Some 6,000 households have been left without power, with an unknown number of households without running water, AFP agency reported.

The cities of Wajima and Suzu and the town of Noto have ordered some 44,000 residents to evacuate and seek shelter in Ishikawa prefecture, Honshu island.

Meanwhile, another 16,000 residents in the Niigata and Yamagata prefectures north of Ishikawa were also told to evacuate, the AFP news agency said.

Wajima and Suzu, in central Japan's Noto peninsula, were among the areas hardest hit by a huge 7.5 magnitude earthquake on New Years Day that killed at least 236 people.

The region is still recovering from the powerful quake which had toppled buildings, ripped up roads and sparked a major fire.

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