Tsunami waves over a metre high hit central Japan on Monday after a huge earthquake that damaged homes, set off a major fire and prompted authorities to urge people to run to higher ground.
Media reports said two people were feared dead after the 7.5-magnitude quake struck Ishikawa prefecture on the Sea of Japan side of the main island of Honshu at 4:10 pm (0710 GMT), according to the US Geological Survey (USGS).
Japanese authorities put the magnitude at 7.6 and said that it was one of more than 50 quakes of 3.2 magnitude or more to rock the region on the New Year's Day holiday -- when families get together and visit shrines -- over several hours.
Television channels interrupted normal services with special programming including of Prime Minister Fumio Kishida urging people in danger areas to "evacuate as soon as possible" to higher ground.
"We realise your home, your belongings are all precious to you, but your lives are important above everything else! Run to the highest ground possible," an alarmed presenter on broadcaster NHK told viewers.
Waves at least 1.2 meters (four feet) high hit the Wajima port and a series of smaller tsunamis were reported elsewhere, including as far away as the northern island of Hokkaido.
The Japan Meteorological Agency (JMA) initially issued a "large tsunami" warning, meaning waves of up to five metres.
But no further major incidents were reported and the JMA later downgraded its warning to tsunamis of up to three metres.
The US Pacific Tsunami Warning Center also said around four hours after the major quake that the tsunami danger had "largely passed".
Russia also issued a tsunami alert for Sakhalin island and Vladivostok in its far east. North Korea reportedly followed suit.
The JMA warned local residents of possible further quakes during the coming week or so, particularly within the next two to three days.
- Fire -
The government said it was still assessing the extent of damage and whether there had been any casualties from the quake, which shook apartments in the capital Tokyo some 300 kilometres (190 miles) away.
Images on social media showed cars and houses in Ishikawa shaking violently and terrified people cowering in shops and train stations. Houses collapsed and huge cracks appeared in roads.
"I have never experienced anything like this before, it was scary. I went out right away but the ground was shaking," an elderly man told broadcaster NHK.
"We are in a horrible situation. Please come and help us. My town is in a horrible situation," said one person in a video shared on X, formerly Twitter, showing several badly damaged houses.
Government spokesman Yoshimasa Hayashi said that there were reports that six people were in the rubble of collapsed buildings, but gave no further details.
Police said they were looking into reports that two people were without vital signs in Nanao city following the quake.
Television channels showed a major fire in Wajima that engulfed a row of houses, with people being evacuated in the dark, some with blankets and others carrying babies.
"There is a large fire. We cannot immediately tell how many houses are affected by it," a firefighter with the Wajima Fire Department told AFP.
Fire engines struggled to reach the scene due to damaged roads and other obstacles, he said.
The department was swamped with calls, with "numerous" reports of people injured and trapped inside collapsed buildings, he added.
Around 33,500 households around the epicentre, in Toyama, Ishikawa and Niigata prefectures, were without power, local utilities said.
Many houses collapsed in the city of Suzu, reports said.
- Bullet trains suspended -
Several major highways were closed around the epicentre, Japan's road operator said, and Shinkansen bullet train services from Tokyo were also suspended.
Flights and mobile phone coverage were reportedly disrupted while many convenience stores were shut.
Defense Minister Minoru Kihara said 1,000 military personnel were preparing to go to the region, while 8,500 others were on standby. Around 20 military aircraft were dispatched to survey the damage.
Japan experiences hundreds of earthquakes every year and the vast majority cause no damage.
The country has strict construction regulations intended to ensure buildings can withstand strong earthquakes and routinely holds emergency drills to prepare for a major jolt.
But the country is haunted by the memory of a massive 9.0-magnitude undersea quake off northeastern Japan in March 2011, which triggered a tsunami that left around 18,500 people dead or missing.
The 2011 tsunami also sent three reactors into meltdown at the Fukushima nuclear plant, causing Japan's worst post-war disaster and the most serious nuclear accident since Chernobyl.
Japan's nuclear authority said on Monday there were no abnormalities reported at the Shika nuclear power plant in Ishikawa or at other plants after the latest quake.