A second blast has rocked the Fukushima nuclear plant in Japan, which was damaged in Friday’s earthquake and tsunami. Follow all of Monday’s events here in a replay of our live blog.
For the latest live blog updates, go to our Japan live blog
To re-cap all the events on Monday, see below
17.00 Update from the British Foreign Office
British casualties: As yet there are no confirmed British fatalities, but the Foreign Office has "severe concerns" about a number of British nationals. Those concerned should call the Foreign Office hotline on +44 (0)20 7008 0000, Skype (text not call) on fcojapan or email firstname.lastname@example.org
Britons in Japan: The Foreign Office emergency helpline has taken almost 5,000 calls, a dedicated crisis unit has been established and a British Search and Rescue team has now arrived at their base, 20km outside Ofunato in the north east of Japan.
Almost 50 extra foreign office staff have arrived in Japan to help British nationals; more are en-route.
Nuclear concerns: The Foreign Office urges Britons in Japan to observe the 20km exclusion zone around Fukushima nuclear facility.
"Lessons learned from more significant incidents, such as Cernobyl, is that an exclusion zone will be effective - even in the event of a more substantial release - in minimising the health effects from direct radiation exposure."
Political response: The Foreign Secretary is due to meet the Japanese Foreign Minister on the fringes of the G8 Foreign Ministers meeting tomorrow. FCO minister Jeremy Browne spoke to the Japanese Ambassador earlier today, and was this morning co-ordinating the cross-government response.
16.50 The Japanese government has formally asked for US help with cooling the damaged nuclear reactors. The US Nuclear Regulatory Commission says it is “considering possible replies” to the request – which includes providing technical advice.
16.23 France’s ASN nuclear safety authority says the nuclear accident in Japan could be classed as level 5 or 6 on the international scale of 1 to 7, on a par with the 1979 US Three Mile Island meltdown. The estimate outstrips Japan’s rating of 4, given earlier today. Channel 4 News’ science correspondent Tom Clarke however, gives us five reasons why this disaster does not match the scale of Chernobyl (which was a 7).
15.58 The head of the UN nuclear watchdog, the International Atomic Energy Agency, says Japan’s massive earthquake and tsunami have shaken and flooded nuclear power plants but their reactor vessels remain intact and radiation release has been limited.
There are no signs, at the moment, that fuel is melting at the nuclear plant, the IAEA said.
As access to disaster-hit areas improves, Medecins Sans Frontieres tells Channel 4 News the race is on to supply water and medicine - particularly for the elderly. Around 1,000 washed up bodies have now been found scattered across the coastline at Minamisanriku. Read more: Japan's race to supply water and medicine as bodies wash up
15.40 Prime Minister David Cameron told MPs that while there are no British casualties so far, there were “severe concerns” for the safety of a number of British nationals in Japan. In a statement to the Commons Mr Cameron said the devastation in Japan was “heartbreaking” and of “truly colossal proportions”. Mr Cameron added: “Britain and the British people are your friends and we have no doubt you’ll recover”.
15.15 The International Atomic Energy Agency (IAEA) says Japan has provided 230,000 units of stable iodine to evacuation centres as a precautioary measure in the country’s nuclear emergency. Iodine can be used to help protect against thyroid cancer in the case of radioactive exposure in a nuclear accident.The UN’s atomic watchdog added: “The iodine has not yet been administered to residents; the distribution is a precautionary measure in the event that this is determined to be necessary.”
14.59 A 63-strong UK International Search and Rescue (UK-ISAR) team arrives at Ofunato City together with the US teams from Fairfax County and Los Angeles County. A team from Hampshire Fire & Rescue joins them, with Byron the search and rescue dog. Hants Fire & Rescue said: “The pictures of the devasted town indicates that there are numerous large buildings damaged but still standing that may yield survivors. At this stage of the operation search dogs will be highly effective at detecting signs of life over the large areas involved.” Follow their relief efforts on Twitter and on Facebook.
14.44 Save the Children is particularly concerned for the psychologicall well being of an estimated 100,000 young people who have been displaced in Japan. The charity has launched a £1m appeal to help children to overcome shock and distress.
14.36 UK workers at a Japanese car maker Nissan in Sunderland are waiting to hear if a group of their British colleagues visiting Japan will be flown home to safety. A group of 45 Nissan employees were last week visiting a site close to the Fukushima plant, which has been rocked by two explosions since Friday. A spokesman said all the Sunderland employees had been contacted and were safe and well. Staff are expected to be briefed on the company’s situation later today.
13.50 Tokyo Electric Power Company is reinjecting water into the No.2 reactor at Fukushima Daiichi nuclear power plant in the hope of cooling it, and says water levels have risen and half the rods are exposed.
Nuclear safety agency rates the incident as a 4 on the International Nuclear and Radiological Event Scale, which runs from 1 to 7 – this is less serious than Three Mile Island (rated 5) and Chernobyl (rated 7) – as Tom Clarke explains below:
Channel 4 News' science correspondent Tom Clarke explains the five key reasons why the blasts in Japan are not Chernobyl.
12.54 Japan’s Sendai Gas says it is unable to reach the Shinminato LNG (liquified natural gas) terminal near the port of Sendai, due to another tsunami warning today. The terminal, which was flooded by seawater on Friday, has not caught fire and appears undamaged from afar, Sendai Gas told Reuters.
12.39 Analysts are split over the fate of the Japanese economy – will it slide back into recession or will efforts to rebuild the shattered quake zone kick start growth? Read more: Japan’s economy feels aftershocks.
Chief correspondent Alex Thomson blogs from Kesannuma, on the east coast of Honshu:
A man walks up. He smells like he's been drinking for days. "This is my house," he says.
But all I see are four huge tuna factory ships standing in an undergrowth of chains, slime, twisted metal and random smashed up cars.
"This – my house," he says again. Read Alex Thomson's blog.
12.18 Switzerland suspends the approvals process for three new nuclear power stations in order to revisit safety standards after the explosion at a Japanese plant. Energy Minister Doris Leuthard says: “Safety is our first priority,” Leuthard said in a statement. Switzerland’s five existing nuclear reactors generate about 40 per cent of the country’s electricity but some will have to be retired in coming years. Decisions on sites for new plants were due to be made in mid-2012.
12.01 Channel 4 News producer Helene Cacace, in Japan with chief correspondent Alex Thomson, tweets: Forest fires on island of Oshima burning as we left Bay of Kesennuma opposite tonight. Follow Helene on Twitter.
Channel 4 News technology correspondent Benjamin Cohen blogs on the fascinating Facebook graphic that shows how news of the disaster hitting Japan has spread around the world. Read Benjamin's blog.
11.31 The nuclear plant Tokai Daini, on the northeast coast of Japan, is expected to be safely cooled down by Tuesday morning, Japan Atomic Power Co says. Its only 1,100 megawatt reacteor was shut down shortly after Friday’s earthquake.
11.15 Tokyo Electric Power Company has held off implementing rolling blackouts but is calling for all to limit electricity use. Shops shut, people told not to go to work. Generators reported to be in great demand.
10.40 Hundreds of foreigners continue to leave Japan amid heightened fears over the safety of the country’s nuclear plants. Long queues are reported at Tokyo’s Haneda Airport.
10.34 Vladimir Putin, Russia’s Prime Minister, says that there is no threat of a global nuclear disaster amid a crisis at Japan’s nuclear facilities. Putin, speaking in the Siberian city of Tomsk, also said Russia would not be altering its ambitious plans to build dozens of nuclear power stations in coming decades.
Jon Snow tweets: Brittle bright day, wind cold from south - bad for radiation drift: second reactor has blown at Fukushima: Four nuke power stations at risk.
Biggest mobilisation of Japanese forces since Second World War: 100,000 on the move. Rescue operation awesome: no Japanese self pity either.
Troops rescue workers steaming up the damaged freeway from every corner of Japan...some driving solidly ever since it happened.
Lasting images in Sendai, Japan, four bundled bodies in blankets heaved into an army truck...a sixth at the roadside wrapped in black plastic. Follow Jon on Twitter.
10.00 European Energy Commissioner Guenther Oettinger says that a special European Union summit on nuclear safety should look into the legal, technical, economic and political consequences of Japan’s nuclear crisis. EU energy ministers, nuclear plant operators and builders and regulators are holding a special meeting on the Japan crisis on Tuesday (Reuters).
09.35 Jon Snow tells us there are cars in the departure lounge at Sendai Airport.
09.30 Channel 4 News Chief Correspondent Alex Thomson, @alextomo, just called in from Kesennuma where a fleet of boats washed up on top of the town. Residents pointing at the boats saying families are under them.
08.15 Foreign Secretary William Hague says that a number of British nationals are unaccounted for in Japan, although there have so far been no confirmed reports of casualties.
06.40 There has been a second explosion at Fukushima nuclear plant, and warnings of another tsunami overnight.
The Japanese Government will pump 15 trillion yen (£113bn) into the economy but the markets still fell on opening in Tokyo.