Road cracks caused by an earthquake is seen in Wajima, Ishikawa prefecture, Japan January 1, 2024, in this photo released by Kyodo. Image Credit: Mandatory credit Kyodo via Reuters

Tokyo: Japan dropped its highest-level tsunami alert, issued following a series of major earthquakes on Monday, but told residents of coastal areas not to return to their homes as deadly waves could still come.

The quakes, the largest of which had a magnitude of 7.6, started a fire and collapsed buildings on the west coast of Japan’s main island, Honshu. It was unclear how many people might have been killed or hurt.

The Japan Meteorological Agency reported more than a dozen quakes in the Japan Sea off the coast of Ishikawa and nearby prefectures shortly after 4pm.

At least six homes were damaged by the quakes, with people trapped inside, government spokesman Yoshimasa Hayashi said. A fire broke out in Wajima city, Ishikawa Prefecture, and electricity was out for more than 30,000 households, he said.

The agency initially issued a major tsunami warning for Ishikawa and lower-level tsunami warnings or advisories for the rest of the western coast of the island of Honshu, as well as the northernmost of its main islands, Hokkaido.

The warning was downgraded to a regular tsunami several hours later, meaning the waters could still reach up to 3 meters (10 feet). Aftershocks could also slam the same area over the next few days, it said.

Japanese public broadcaster NHK TV initially warned torrents of water could reach as high as 5 meters (16.5 feet).

NHK said the tsunami waves could keep returning, and warnings were continuing to be aired hours after the initial alert. Several aftershocks also rocked the region.

Hayashi stressed that it was critical for people in coastal areas to get away from the oncoming tsunami.

“Every minute counts. Please evacuate to a safe area immediately,” he said.

People returning to get their wallets and other belongings have been known to be swept away and drowned even hours after the first evacuation warning. People were evacuated to stadiums, where they will likely have to stay for a few days.

Hayashi said no reports of deaths or injuries had been confirmed from the quakes, saying the situation was still unclear. Japan's military was taking part in the rescue efforts, he said.

Japanese media footage showed people running through the streets, and red smoke spewing from a fire in a residential neighborhood. Photos showed a crowd of people, including a woman with a baby on her back, standing by huge cracks that had ripped through the pavement.

Some people sustained minor injuries when they tripped and fell while fleeing, or objects fell off shelves and hit them, according to NHK.

Bullet trains in the area were halted, although some parts of the service were restored by evening. Parts of the highway were also closed, and water pipes had burst, according to NHK. Some cell phone services in the region weren't working.

The Meteorological Agency said in a nationally broadcast news conference that more major quakes could hit the area over the next week, especially in the next two or three days.

More than a dozen strong quakes had been detected in the region, with risks of setting off landslides and houses collapsing, according to the agency.

Takashi Wakabayashi, a worker at a convenience store in Ishikawa Prefecture, said some items had tumbled from the shelves, but the biggest problem was the huge crowd of people who had shown up to stock up on bottled water, rice balls and bread.

“We have customers at three times the level of usual,” he said.

Tsunami warnings were also issued for parts of North Korea and Russia.

The Japanese government has set up a special emergency center to gather information on the quakes and tsunami and relay them speedily to residents to ensure safety, Prime Minister Fumio Kishida told reporters.

Japan is an extremely quake-prone nation. In March 2011, a major quake and tsunami caused meltdowns at a nuclear plant . The latest warning was the first time since the 2011 disaster that a tsunami warning of this magnitude was issued.

Government spokesman Hayashi told reporters that nuclear plants in the affected area had not reported any irregularities on Monday. Nuclear regulators said no rises in radiation levels were detected at the monitoring posts in the region.

Residents told to run

The largest of the quakes prompted broadcasters to switch to special programming and make urgent calls for affected residents to leave for 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," a presenter on broadcaster NHK told viewers.

A tsunami warning is shown on TV in Yokohama, near Tokyo Monday, Jan. 1, 2024. Japan issued tsunami alerts Monday after a series of strong quakes in the Sea of Japan. Image Credit: AP

No abnormalities reported in nuclear plants

Hokuriku Electric Power said it is checking for any irregularities at its nuclear power plants, NHK reported.

A spokesperson for Kansai Electric Power said there were currently no abnormalities at its nuclear power plants but the company was monitoring the situation closely.

"It has been confirmed that there are no abnormalities at Shika nuclear power plant (in Ishikawa) and other stations as of now," government spokesman Yoshimasa Hayashi said.

South Korea's east coast braces for tsunami
The first tsunami reached South Korea's east coast at 0921 GMT at a height of 45 cm (1.5 ft) in the wake of a massive earthquake that hit Japan on Monday, South Korea's meteorological agency said.

The tsunami can grow after the initial waves and may continue for more than 24 hours, the agency said in an advisory.

South Korea's Gangwon province warned residents to take precautions and evacuate to higher ground, according to the Ministry of Interior and Safety.

South Korea's meteorological agency earlier said sea levels in some parts of the Gangwon province on the east coast may rise after an earthquake with a preliminary magnitude of 7.6 hit north central Japan and it issued an advisory for caution.

It said tsunami waves of up to 0.3 metres could reach South Korea's eastern shore between 0929 GMT and 1017 GMT.

Gangwon province told residents in emergency text messages to stay away from the coast and evacuate to higher ground. The city of Samcheok advised residents to move to areas higher than a three-storey building, the Ministry of Interior and Safety said.

North Korea issues tsunami warnings 

North Korea issued tsunami warnings for its east coast after a massive quake hit north central Japan on Monday, saying waves of up to 2.08 meters (6.8 ft) can reach its shore, Yonhap news reported citing the North's state radio.

Far-eastern Russia on 'alert'

Russia's Sakhalin island near Japan and the Pacific city of Vladivostok were on "alert" Monday due to a possible tsunami risk after a major earthquake in Japan.

Authorities in Sakhalin said the island's west coast could be affected by tsunami waves, but stressed they would not cause a major threat to life on the island and did not order evacuations.

Emergency services called on people to "remain calm".

"Coastal parts of the western coast of Sakhalin may be affected by tsunami waves," emergency services said.

"At the moment... the population is not being evacuated, since the expected height of the wave is no more than 50 centimetres," it said.

Waves were expected to reach the southern tip of the island, in the Nevelsky district, at 8:44 pm local time (0944 GMT).

Authorities stressed that the expected height of the waves "do not pose a life threat to the population."

The city of Vladivostok also introduced a tsunami alert.

"Fishermen and everyone who plans to go out to sea, has to urgently come back to shore," city authorities said on social media.

It said it expected waves to rise to "0.3 meters"

Major deadly earthquakes

Japan 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.

In March 2022, a 7.4-magnitude quake off the coast of Fukushima shook large areas of eastern Japan, killing three people.

The capital Tokyo was devastated by a huge earthquake a century ago in 1923.