Officials in northeastern Japan are searching for thousands of people missing more than a day after a devastating earthquake and tsunami.

The confirmed death toll from Friday's twin disasters is 763, but the government's chief spokesman said it could exceed 1,000.

In Ottawa, the government confirmed that a Canadian had died in Japan. Diane Ablonczy, the minister of state of Foreign Affairs, told News Network that Foreign Affairs has been in contact with the family of the victims, whose name and hometown haven't been released.

Foreign Affairs has issued a travel warning for Canadians to avoid non-essential travel to Miyagi, Ibaraki, Iwate, Fukushima and Aomori prefectures in northeast Japan.

Devastation stretched hundreds of kilometres along the coast, where thousands of hungry survivors huddled in darkened emergency centres cut off from rescuers, electricity and aid.

The scale of destruction was not yet known, but there were grim signs that the death toll could soar. One report said four whole trains had disappeared Friday and still not been located. It's not known how many people were on the trains but the Kyodo news agency reported that several passengers and crew members had been rescued.

A man and child look out over destroyed homes in Sendai, northeastern Japan, on Saturday. Kyodo/Reuters

Other reports said 9,500 people were unaccounted for in the coastal town of Minamisanriku in Miyagi Prefecture. Kyodo said that represents more than half of the community's population.

One of the few buildings not destroyed in Minamisanriku was the hospital, but seawater had reached the fourth of its five floors. On Saturday afternoon, there were around 300 patients stranded there waiting to be rescued, according to Japanese broadcaster NHK.

At least 200 bodies had washed ashore elsewhere in the northeast.

About 215,000 people have gone to emergency shelters following the 8.9-magnitude earthquake and the tsunami.

Billions of dollars in damage

The quake struck 125 kilometres off Japan's northeast coast. The majority of victims drowned in giant tsunami waves that swept 10 kilometres inland, created by the powerful tremor. Thousands of buildings and cars were washed away, along with the four passengers trains.

Officials are closely watching nuclear power plants after an explosion and secondary emergency at one of two nuclear plants damaged by the quake. The government on Saturday doubled in size the evacuation area around the Fukushima Daiichi nuclear power plant to a 20-kilometre radius.

Kyodo quoted the power company as saying four workers were hurt but their injuries were not life-threatening.

Police said between 200 and 300 bodies were found along the coast in Sendai, the biggest city in the area near the quake's epicentre. It has a population of one million and is relatively flat.

Kyodo, quoting the Fire and Disaster Management Agency and local police, said the coastal city of Rikuzentakata was "virtually destroyed" by a tsunami wave.

"Our initial assessment indicated that there has already been enormous damage," said chief cabinet secretary Yukio Edano.

Many buildings, including an oil refinery plant in Sendai, were still burning Saturday. An out-of-control blaze burned through the night in the city of Kesennuma. Japanese broadcaster NHK said local authorities had no way of tackling it.

In the city of Ichihara, flames shot 30 metres into the air from a fire at an oil refinery. TV video showed a large building on fire in the Odaiba district of Tokyo.

Smoke billows from an oil refinery plant on fire in Sendai on Saturday. (Koji Sasahara/Associated Press)

Early morning television scenes bordered on the apocalyptic. Jumbled piles of vehicles could be seen in farmland flooded with several metres of water. People are still stranded on rooftops. Many others were seen standing on cut-off rural roads, surrounded by huge seas of standing water.

Rescue helicopters hovered over inundated homes, lifting people to safety.

A ship with 81 people onboard was ripped from its moorings at a shipyard in Miyagi. It was later found at sea and those on board are being airlifted to safety, AFP reported, citing a report from the Jiji news agency.

Residents stranded in a building wait for rescue in Kesennuma, Japan, on Saturday morning. Kyodo News/Associated Press

Many aftershocks

There have been at least 125 powerful aftershocks since the quake struck. Among the strongest was a 6.6-magnitude tremor, which rattled Tokyo early Saturday. No tsunami warnings were issued and there were no reports of injuries.

In Hawaii, a two-metre-high wave hit parts of Maui and smaller waves hit Oahu and Kauai. In northern California, authorities were searching for a man believed swept out to sea. No significant wave action was felt in B.C.

Quake moved Honshu 2.5 metres

Japan is used to earthquakes and has instituted strict building codes and carries out frequent earthquake and tsunami drills. But the sheer intensity of Friday's disaster was such that even the best preparation could only mitigate the tragedy.

Officials said the initial quake was the most powerful one to hit the region in 1,200 years. The USGS says the force of the quake was so strong that Honshu — Japan's biggest island — was moved 2.5 metres to the east.

The quake was 8,000 times more powerful than the one that struck Christchurch, New Zealand, in February.

Aid agencies

The Canadian Red Cross quickly launched a Japan Earthquake/Tsunami fund. In the first nine hours, officials told CBC News that Canadians had donated $176,000.

The International Committee of the Red Cross (ICRC) has also set up a Family Links website to help people trying to re-establish contact with missing family members and friends. The ICRC says the worst hit areas are in the prefectures of Miyagi, Fukushima, Tochigi and Ibaraki.

With files from The Associated Press