Japanese police have raised the known death toll from last week's devastating earthquake and tsunami to 2,414. Another 3,118 are listed as missing, but unofficial numbers put the true number of missing at well over 10,000.

Police in one prefecture estimated that more than 1,000 bodies have washed ashore in the wake of Friday's tsunami.

Police in Miyagi prefecture have already found several hundred bodies on local beaches, according to NHK, Japan's public broadcaster. Prefecture officials also say 1,000 bodies have been found in the town of Minamisanriku.

Japanese police have estimated that the death toll could exceed 10,000. The true scope of the disaster is not yet clear as many communities are still unreachable.

The Kyodo news agency says local governments "are unable to contact up to 30,000 residents."

The official death toll does not include the more than 2,000 bodies reportedly scattered across coastal towns.

The United Nations humanitarian affairs office said many hard-hit towns and villages are cut off by water from the tsunami that followed Friday's powerful quake.

More than 800 roads, dozens of bridges and seven railways are badly damaged, the UN agency said, further complicating efforts to get to affected communities.

In many areas, there is no running water, no power, and four- to five-hour waits for gasoline. There were reports that some communities were also dealing with shortages of food and medicine.

"People are surviving on little food and water. Things are simply not coming," said Hajime Sato, a government official in Iwate prefecture, one of the three hardest hit.

He said local authorities were also running out of body bags and coffins, while other communities said crematoriums couldn't keep up as more bodies were recovered.

"I'm giving up hope," said Hajime Watanabe, a 38-year-old construction worker who was the first in line at a closed gas station in Sendai, about 100 kilometres north of Soma.

"I never imagined we would be in such a situation. I had a good life before. Now we have nothing. No gas, no electricity, no water."

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He said he was surviving with his family on 60 half-litre bottles of water his wife had stored for an emergency. He walked two hours to find a convenience store that was open and waited in line to buy dried ramen noodles.

Sayaka Matsumoto, a spokeswoman for the Japanese Red Cross, said extra medical teams have been dispatched to affected communities to try to help the hospitals.

Even with the extra help, she said many hospital staff were struggling to treat all the patients.

"The staff is very tired," she said Monday, adding that some hospitals were "overwhelmed" after the quake.

Matsumoto said the situation was further complicated by the powerful aftershocks rumbling through the area.

"Sometimes there is a tsunami alarm again, so the rescue process has to stop every time a tsunami alarm is raised," she said. "We just hope it stops."

The pulverized coast has been hit by hundreds of aftershocks since Friday. The latest was a 6.2-magnitude quake that was followed by a new tsunami scare Monday. As sirens wailed, soldiers abandoned their search operations and told residents of the devastated shoreline in Soma, the worst-hit town in Fukushima prefecture, to run to higher ground.

They barked out orders: "Find high ground! Get out of here!" Several soldiers were seen leading an old woman up a muddy hillside. The warning turned out to be a false alarm.

"This is Japan's most severe crisis since the war ended 65 years ago," Prime Minister Naoto Kan told reporters Sunday, adding that Japan's future would be decided by its response.

On Monday, the U.S. Geological Survey increased the magnitude of Friday's quake to 9.0 from 8.9 following a similar move by Japanese seismologists. "This magnitude places the earthquake as the fourth largest in the world since 1900," the USGS said.

At least 1.4 million households had gone without water since the quake struck and some 1.9 million households were without electricity.

Many citizens have adopted a "war-era mentality," the CBC's Amber Hildebrandt wrote.

"Lineups snake outside gas stations, bakeries and even along hillsides by rain water drainage pipes. Many restaurants and convenience stores are closed. Those with power face rolling outages as the government tries to conserve electricity."

Nuclear concerns continue

The loss of electricity is being blamed partly on damage to at least three nuclear reactors at the Fukushima Dai-ichi power plant.

Relatives are reunited at a shelter in Miyagi prefecture on Monday. Thousands are still missing following last week's deadly earthquake and tsunami in northeastern Japan. (Kyodo News/Associated Press)

Early Tuesday morning, Japan time, a third explosion shook the Dai-ichi plant. On Monday, water levels dropped precipitously inside Unit 2 of the reactor, twice exposing the uranium fuel rods and raising the threat of a meltdown. A few hours later, a fire broke out at a fourth reactor at the same plant, prompting officials to warn of potential health dangers for people as radiation levels spiked.

Social media A recap of the events leading up to the current nuclear situation

The cascading troubles in the Fukushima Dai-ichi plant compounded the immense challenges faced by the Tokyo government, already struggling to send relief to hundreds of thousands of people along the country's quake- and tsunami-ravaged coast.

In the last three days, at least 180,000 people who live near the stricken reactors have been ordered to leave their homes.

Quake-affected towns were also struggling to meet people's basic needs in the days following the quake, CBC's John Northcott said from Mito, a city about 100 kilometres north of Tokyo. He said city roads were in decent shape, but there were signs of the quake everywhere.

"This is the southernmost end of the northeastern section of Japan that was so badly hit last week," Northcott said.

"It is evident on every street that there has been an earthquake. Everything from broken water mains, to divots taken out of the roads, to smashed windows."

He said chunks of concrete had fallen off some buildings, while other structures looked as if they were about to collapse.

Dozens of aftershocks are still a daily occurrence, the CBC's Curt Petrovich reported from Oyama, Japan. "The one Monday morning — with a magnitude [of] 6 — was strong enough to sway the chandeliers of a Narita hotel and prompt another tsunami alert," he said.

Preliminary estimates put insurance costs from Friday's disaster at up to $60 billion, a huge blow for an already fragile economy.

Ninety-one countries have offered assistance. The UN said 15 international specialist teams have deployed to Japan to help with the recovery efforts.

Canadian officials have said they are ready to provide a range of assistance to Japan, including nuclear expertise, and military personnel and equipment if needed.

The Canadian government announced Monday it has offered to send DART — the Disaster Assistance Response Team — and is waiting for a response from Japan. DART provides emergency services, such as drinking water and medical treatment, until long-term aid arrives.