That concludes our latest updates for this evening. We'll be back with more coverage from Japan tomorrow.
The United States has authorised the first evacuations of Americans out of Japan, taking a tougher stand on the deepening nuclear crisis and warning US citizens to defer all non-essential travel to any part of the country as unpredictable weather and wind conditions risked spreading radioactive contamination.
President Barack Obama on Wednesday placed a telephone call to Prime Minister Naoto Kan to discuss Japan's efforts to recover from last week's devastating earthquake and tsunami, and the nuclear crisis at the Fukushima Daichi plant. Obama promised Kan that the US would offer constant support for its close friend and ally, and "expressed his extraordinary admiration for the character and resolve of the Japanese people," the White House said.
Its authorised departure offers a voluntary evacuation to family members and dependents of US personnel in Tokyo and Yokohama and affects some 600 people.
The State Department yesterday issued a warning to Americans to avoid travel to Japan.
"There is no water in the spent fuel pool and we believe that radiation levels are extremely high, which could possibly impact the ability to take corrective measures," Gregory Jaczko said at a House Energy and Commerce subcommittee hearing.
If correct, this would mean there was nothing to stop the fuel rods from heating and ultimately melting down. The outer shell of the rods could also ignite with enough force to propel the radioactive fuel inside over a wide area.
But Japan's nuclear safety agency and Tokyo Electric Power Co., which operates the six-unit complex, denied Jaczko's statements that the pool is dry
After the hearing, Jaczko left some room for error. If he is wrong, it would represent a very embarrassing moment for the US government.
"My understanding is there is no water in the spent fuel pool," he said. "I hope my information is wrong. It's a terrible tragedy for Japan."
It also shifted Japan more than two metres away from the neighbouring Korean peninsula, scientists say.
The Korea Astronomy and Space Science Institute (KASSI) said the Korean peninsula moved east up to five centimetres while Japan shifted some 2.4 metres east.
"We are closely monitoring to see whether the shift was temporary or perpetual," a KASSI spokeswoman told AFP.
"But don't worry. You will never feel the change anyway," she said.
The G-7 finance ministers and central bank heads will start talks at 7.30am on Friday Japan time, the Kyodo News Agency reported.
The talks were called by Christine Lagarde, the finance minister of France, which holds the rotating presidency of the forum.
Yesterday, Chugoku Electric Power Co said it would put on hold plans for a new nuclear plant, which had previously met with resistance from residents.
But less clear is whether the government will scale back a 2030 goal of boosting nuclear power generation to half of national electricity output from nearly 30 percent now.
A part of Minami Soma falls within the plant's 20-kilometre evacuation zone, and another part is in the 20-30 kilometre zone where people are being urged to stay indoors.
They will be shifted out of Fukushima Prefecture, as shelters within the prefecture are already full.
Obama made the offer in a telephone call with Japanese Prime Minister Naoto Kan, Edano told reporters.
US Ambassador to Japan John Roos said 34 nuclear experts had already arrived in the country carrying equipment to monitor radiation levels near the Fukushima No.1 plant, 250 kilometres northeast of Tokyo.
The experts are set to monitor the fluctuating levels from ground and air.
The number of confirmed dead from Friday's twin disasters stood at 5,178, while the official number of missing remained at 8,606, the national police agency said in its latest update.
A total of 2,285 people were injured in the disaster.
But reports continued to come in which indicated that the final toll could be much higher.
The mayor of the coastal town of Ishinomaki in Miyagi prefecture said late Wednesday that the number of missing there was likely to hit 10,000, Kyodo News reported.
Fears over radiation spread via the internet and text messages, prompting Seoul to launch a crackdown on scaremongering, as officials insisted that constant westerly winds will blow radiation out into the Pacific.
A riot squad from the Tokyo police force will be sent to the plant's No. 3 and No. 4 reactors within hours.
Tokyo Electric Power says 43 percent of the fuel rods in the No.1 reactor were possibly damaged at 1pm local time on Tuesday, but the ratio had increased to 70 percent by 3.25pm.
At the No.2 reactor, the ratio rose to 33 percent from 14.
Pressure and coolant levels are low in both reactors, and the fuel roads are exposed. Water is being poured into them.
Tokyo Electric Power Co. says it's concentrating on restoring the power supply to reactivate the facility's crippled cooling systems.
The Xinhua News Agency reported the shipment will include 10,000 tons of gasoline and 10,000 tons of diesel fuel.
China previously pledged $4.5 million worth of blankets, tents, emergency lighting and other humanitarian assistance. It also sent 15 rescuers to help search for survivors.
India has also offered 25,000 blankets and Thailand another 20,000.
An aircraft with relief supplies from Thailand is enroute to Japan.
Prior to this, the Thai government had already provided 1,000 blankets and announced its intention to extend relief money of 5 million baht.
Freezing temperatures and heavy snow fall are adding to the burden for displaced Japanese residents following last week's earthquake and tsunami.
Officials say 128 hospital patients evacuated on Monday to a high school in Iwaki city. Two reportedly died enroute on a bus, and 12 others died shortly after arrival.
Japanese auto companies have extended shutdowns of car assembly plants affected by the country's devastating earthquake and tsunami, but in a sign of progress, some parts factories in Japan plan to resume production later this week.
Helicopters are now dumping water on the stricken number 3 reactor at the Fukushima Dai-ichi plant.
Japanese officials struggling to avoid full meltdowns have raised hopes of easing the crisis, saying they may be close to bringing power back to the plant and restoring the cooling systems.
A 5.0 magnitude aftershock has struck at around 1pm (NZ time), 250km off the coast of Honshu, Japan.
One impact the crisis in Japan may have on us is electronics supplies. For more, check this story out: How the Japan Quake Is Disrupting the Supply of Notebook Batteries and LCD Displays.
Here's some touching amateur video of how a dog stands guard by the side of another badly injured dog in the aftermath of the tsunami (NOTE: comments in Japanese).
A Japanese government spokesperson told NHK World the Self Defence Force will soon recommence an operation to drop water from a helicopter on the damaged reactors at the Fukushima Daiichi plant in an effort to cool fuel rods. The operation was postponed last night due to dangerous levels of radiation.
Japanese shares slumped more than four per cent in early trade today as workers scrambled to avoid a nuclear catastrophe.
The benchmark Nikkei index fell 4.39 per cent in the first 25 minutes of trading as jittery investors again offloaded shares amid fears about the unfolding crisis at the Fukushima plant.
Meanwhile, the yen hit its highest level against the dollar since World War II.
The International Atomic Energy Agency remains concerned about the temperature of spent fuel stored in pools at the Fukushima Daiichi plant.
The IAEA says spent fuel that has been removed from a nuclear reactor generates intense heat and is typically stored in a water-filled spent fuel pool to cool it and provide protection from its radioactivity.
If fuel is no longer covered by water or temperatures reach a boiling point, fuel can become exposed and create a risk of radioactive release.
The number of Australians unaccounted for in devastated parts of Japan has halved.
"That number has come down overnight from 103 to 55," Foreign Minister Kevin Rudd told the Nine Network.
"We're going to continue to work on this during the course of the day."
Mr Rudd said Foreign Affairs was advising Australians in devastated areas to leave Japan because of infrastructure breakdowns.
Here's a contribution to the current debate on atomic power, from Yes magazine.
Estimates are that half a million people in Japan are currently displaced by the disaster. Adding to their woes, an unseasonal snowstorm has sent temperatures plunging to below zero and blanketed much of northeast Japan in white.
12,000 people remain missing, feared dead, six days after the tsunami struck.
The International Red Cross has published this Q&A on Frequently Asked Questions on the Earthquake in Japan.
This article discusses the impact of the earthquake and tsunami on pets.
More celebrities have pledged to raise money for Japan:
Blink-182 singer Mark Hoppus is auctioning off band memorabilia to raise money, including his original handwritten lyrics from the song 'Rock Show', which has already reached bids of $20,000.
Rock band Linkin Park's vocalist and guitarist, Mike Shinoda, has designed two tee-shirts which will benefit charity to aid their efforts in Japan. One design features a butterfly and the band's logo, while the other has the words 'Not Alone' across the chest.
And troubled actor Charlie Sheen has also pledged to donate one dollar to the Japanese cause from every ticket sold for his forthcoming series of one-man shows.
Right wing US broadcaster Rush Limbaugh has caused a controversy by apparently mocking Japan's environmental-friendly attitude when talking to a caller to his radio show.
Micro-blogging website Twitter has been experiencing some performance problems, due to extraordinarily high traffic as users track dramatic developments in the nuclear emergency in Japan.
"You may experience some problems loading twitter.com and with Twitter clients," Twitter said on its status blog. "We are aware of the problem and are taking action."
(While it was unavailable in New Zealand first thing this morning, since then it has been fine.)
The US military has banned access to 13 websites - including YouTube, eBay, Amazon, MTV and ESPN (but not Facebook) on its computer network - to free up bandwidth for relief efforts in Japan, Al Jazeera reports.
The Pentagon says the move is "in no way a reflection on any specific site" or its content.
"[It is] in response to the needs of the military in a time of extreme demand on all circuits and networks in a region of the world that has been devastated by geological activity."
Australia, Britain and Germany have now advised their citizens in Japan to consider leaving Tokyo and earthquake-affected areas, joining a growing number of governments and businesses telling their people it may be safer elsewhere.
A list of all the aid organisations giving assistance to Japan is available here.
The director general of the International Atomic Energy Agency, Yukiya Amano, is planning to fly to Japan "as soon as possible" to see the situation for himself and see how the agency can best assist Japanese authorities.
Hip-hop stars the Black Eyed Peas have appended a message to the end of their new video, which debuts on US television tomorrow, urging fans to donate to the Red Cross to help victims of the catastrophe in Japan.
The video for the song Just Can't Get Enough was shot in Japan a week ago.
"Our heart goes out to all of the Japanese people who have been affected by this natural disaster," said Black Eyed Peas' Fergie.
Airlines are racing to clear Tokyo's airports of a backlog of passengers and help those wanting to leave, as fears grew that quake-stricken Japan was losing control of a steadily growing nuclear crisis. Many aircraft flying to Japan are almost deserted, while there is huge demand for seats on flights out.
A special police van equipped with a water cannon - normally used on rioters - has arrived at the Fukushima Daiichi plant this morning, BBC News reports.
The Tokyo Electric Power Company plans to use the cannon to spray water onto reactor 4's spent fuel storage pond.
The BBC reports the cannon is believed to be strong enough to allow engineers to remain a safe distance from the complex and limit their exposure to radiation.
Here's a website that shows many of the best info-graphics on the developing earthquake/tsunami/nuclear disaster in Japan.
The US military is to send an unmanned high-altitude reconnaissance aircraft over the Fukushima Daiichi plant to take a closer look at its troubled reactors, the Japanese government told Kyodo News.
Infra-red images taken by the craft could provide a better idea of what is occurring inside the reactor buildings, which have been difficult to access because of radiation levels.
The All Whites' soccer clash against Japan this month could be turned into a charity match in an attempt to "rally the nation" in the wake of last week's devastating earthquake and tsunami.
The Japan Football Association (JFA) still plans to play the "friendly" against New Zealand on March 29.
The chief of the US Nuclear Regulatory Commission says all the water is gone from one of the spent fuel pools at Japan's most troubled nuclear plant. This means there is nothing to stop the fuel rods from getting hotter and ultimately melting down.
The outer shell of the rods could also ignite with enough force to propel the radioactive fuel inside over a wide area.
Japan's nuclear crisis is reverberating in atomic power-friendly countries, with China saying it would hold off on approving new nuclear plants and French politicians questioning top energy executives about the safety of their reactors.
Some governments have put their nuclear future on hold, at least for now, as concerns grow even among pro-nuclear governments about the safety of the 442 reactors operating around the world.
Lady Gaga has raised US$250,000 ($323,918.11) in 48 hours for victims of the earthquake and tsunami in Japan by selling plastic wristbands that say "We pray for Japan", the pop superstar tweeted.
"Monsters: in just 48 hrs you';ve raised a quarter of a million dollars for Japan Relief," Gaga said on Twitter.
"It's important we help."
Gaga launched the white wristbands with their prayerful message written in red in English and Japanese, via a Twitter message on Monday, three days after a 9.0-magnitude quake struck off the coast of northeastern Japan, triggering a killer tsunami.
The wristbands are available for US$5 and can be pre-ordered on Gaga';s official online store.
The governor of the Fukushima Prefecture, Yuhei Sato, has slammed the official handling of the evacuation around the Fukushima Daiichi nuclear power plant, BBC News reports.
A 20km evacuation zone has been placed around the quake-hit plant forcing thousands of residents to flee their homes.
Mr Sato said evacuation centres did not have enough hot meals and basic necessities such as fuel and medical supplies.
"We're lacking everything," he said. "Anxiety and anger felt by people have reached boiling point."
The operator of Japan's tsunami-crippled nuclear plant says it has almost completed a new power line that could restore electricity to the complex and solve the crisis that has threatened a meltdown.
Tokyo Electric Power Co. spokesman Naoki Tsunoda said the power line to Fukushima Dai-ichi is almost complete.
The new line would revive electric-powered pumps, allowing the company to maintain a steady water supply to troubled reactors and spent fuel storage ponds, keeping them cool.
The European Union is urging member states to check Japanese food imports for radioactivity following the country's nuclear crisis.
"A recommendation was issued via the rapid alert system for food and animal feed," said the European Commission spokesman for health issues, Frederic Vincent.
The advice requires governments that conduct controls to inform the 27-nation EU if the level of radiation exceeds authorised levels.
CNN reports the death toll in Japan stands at 4,314, according to the National Police Agency Emergency Disaster Headquarters. At least 8,606 people were missing and 2,282 injured, officials said.
The level of radiation 20km from the Fukushima Daiichi nuclear power plant does not pose an immediate health risk to people, Japan's Chief Cabinet Secretary Yukio Edano says.
A maximum of radiation level of 0.33 millisieverts per hour has been registered outside of the 20km evacuation zone by the science ministry, NHK World reports.
People within 20 to 30km of the plant are being advised to stay indoors.
Japan's Self-Defence Force say they are ready to begin work dumping water on Fukushima Daiichi unit 3 reactor after the operation was called off yesterday afternoon due to radiation levels, NHK World reports.
A SDF CH47 helicopter took off from the Sendai base hauling a large container of water, tasked with pouring water on the reactor with the hope of submerging exposed fuel rods.
South Korea will send its reserve of boric acids to Japan to help stabilise quake-damaged nuclear reactors at Fukushima Daiichi nuclear power plant, the government told Yonhap News Agency yesterday.