* Major tsunami warning issued, later reduced to advisory

* Scores of houses destroyed

* Tens of thousands of homes without power overnight

* One man reported dead after building collapses

(Adds graphic, quake milestone paragraph 5, evacuations paragraph 12, Imperial Household paragraph 15, updates power outages paragraphs 21-22)

TOKYO, Jan 1 (Reuters) - A powerful earthquake struck central Japan on Monday, killing at least one person, destroying buildings, knocking out power to tens of thousands of homes and prompting residents in some coastal areas to flee to higher ground.

The quake with a preliminary magnitude of 7.6 triggered waves of about 1 metre along Japan's west coast and neighbouring South Korea, with authorities saying larger waves could follow.

The Japan Meteorological Agency (JMA) issued tsunami warnings for the prefectures of Ishikawa, Niigata and Toyama.

A major tsunami warning - the first since the March 2011 earthquake and tsunami that struck northeastern Japan - was issued for Ishikawa but was later downgraded and eventually cut to an advisory, meaning waves up to 1 metre (3 foot) high could be expected.

It was the strongest quake in the region in more than four decades, according to the U.S. Geological Survey.

Russia and North Korea also issued tsunami warnings for some areas.

Houses were destroyed, fires broke out and army personnel were dispatched to help with rescue operations, government spokesperson Yoshimasa Hayashi told reporters.

One elderly man was pronounced dead after a building collapse in Shika Town in Ishikawa, broadcaster NTV reported citing local police.

"The snow from the electric wire (came) down, and also from the roof it fell down and all the cars are shaking, and so everybody was panicked," Jonny Wu, a Taiwanese tourist visiting nearby Nagano prefecture for a skiing holiday, told Reuters.

Japanese Prime Minister Fumio Kishida told reporters he had instructed search and rescue teams to do everything possible to save lives, even though access to quake-hit areas was difficult due to blocked roads.

More strong quakes in the area, where seismic activity has been simmering for more than three years, could occur over coming days, JMA official Toshihiro Shimoyama said.

The government said that as of Monday night it had ordered more than 97,000 people in nine prefectures on the western coast of Japan's main island Honshu to evacuate.

In comments to the press shortly after the quake struck, Kishida also warned residents to prepare for more disasters.

"I urge people in areas where tsunamis are expected to evacuate as soon as possible," Kishida said.

The Imperial Household Agency said that following the disaster it would cancel Emperor Naruhito and Empress Masako's slated New Year appearance on Tuesday.

'TSUNAMI! EVACUATE!'

Following the quake, a bright yellow message reading "Tsunami! Evacuate!" flashed across television screens advising residents in specific areas of the coast to immediately evacuate.

Local media footage showed a building collapsing in a plume of dust in the city of Suzu and a huge crack in a road in Wajima where panicked-looking parents clutched their children.

There were reports of at least 30 collapsed buildings in Wajima, a town of around 30,000 known for its lacquerware, and fire engulfed several buildings.

The quake also jolted buildings in the capital Tokyo, some 500 km from Wajima on the opposite coast.

Almost 32,000 households were still without power in Ishikawa prefecture late on Monday, according to utilities provider Hokuriku Electric Power, with temperatures set to drop to near freezing overnight in some areas.

Tohoku Electric Power said 700 households remained without power in neighbouring Niigata prefecture.

Telecoms operators also reported phone and internet outages in some areas.

Forty train lines and two high-speed rail services to the quake-hit area halted operations, while six expressways were closed and one of Ishikawa's airports was forced to shut due to a crack in the runway, transport authorities said.

Japanese airline ANA turned back planes headed to airports in Toyama and Ishikawa, while Japan Airlines cancelled most of its services to the Niigata and Ishikawa regions.

NUCLEAR PLANTS

The quake comes at a sensitive time for Japan's nuclear industry, which has faced fierce opposition from some locals since a 2011 earthquake and tsunami triggered nuclear meltdowns in Fukushima. Nearly 20,000 people were killed and whole towns devastated in the disaster.

Japan last week lifted an operational ban imposed on the world's biggest nuclear plant, Kashiwazaki-Kariwa, which has been offline since the 2011 tsunami.

Japan’s Nuclear Regulation Authority said no irregularities have been confirmed at nuclear power plants along the Sea of Japan, including five active reactors at Kansai Electric Power’s Ohi and Takahama plants in Fukui Prefecture.

Hokuriku's Shika plant in Ishikawa, the closest nuclear power station to the epicentre, had already halted its two reactors before the quake for regular inspections and saw no impact from the quake, the agency said.

Monday's quake struck during the Jan. 1 public holiday when millions of Japanese traditionally visit temples to mark the new year.

In Kanazawa, a popular tourist destination in Ishikawa, images showed the remnants of a shattered stone gate strewn at the entrance of a shrine as anxious worshippers looked on.

Kanazawa resident Ayako Daikai said she had evacuated to a nearby elementary school with her husband and two children soon after the earthquake hit. Classrooms, stairwells, hallways and the gymnasium were all packed with evacuees, she said.

"We haven't decided when to return home yet," she told Reuters when contacted by telephone.

(Reporting by Tim Kelly, Satoshi Sugiyama, Kantaro Komiya, Sakura Murakami, Chang-Ran Kim and the Tokyo newsroom; Additional reporting by Nicoco Chan in Shanghai; Writing by John Geddie and Hugh Lawson; Editing by Kim Coghill, Neil Fullick, Louise Heavens and Alison Williams)