Second Explosion At Fukushima Nuclear Plant

A second hydrogen explosion has occurred at a quake-hit nuclear plant in Japan, as the US moved ships and aircraft away due to low level radiation.

Plumes of grey smoke were sent billowing by the blast at the Fukushima Daiichi plant's number 3 unit, although officials insist the inner reactor container remains intact. Japan's Nuclear and Industrial Safety Agency say there is "absolutely no possibility of a Chernobyl" style accident at the site, according to government minister Koichiro Genba. The reactor had been under emergency watch for a possible explosion as pressure built up there following a hydrogen blast on Saturday in the facility's number 1 unit. Japan's chief cabinet secretary Yukio Edano said the reactor's inner containment vessel holding nuclear rods is safe, allaying some fears of the risk to the environment and public. He said the possibility of a radioactive leak was "low". But he added that people within a 20km (12 mile) radius were being ordered to stay inside. Tokyo Electric Power Company says seven people are missing and three are injured after the blast at the plant which is 150 miles (241km) north of Tokyo.

Sky News' Anna Botting, in Sendai, says the authorities are warning people not to drink tap water and to take iodine if they have access to it as it can prevent the threat of thyroid cancer. Officials have been racing to stave off multiple reactor meltdowns after a devastating quake and tsunami incapacitated the Fukushima plant. They had to resort to cooling the reactors down with sea water. More than 180,000 people have evacuated the area, and up to 160 may have been exposed to radiation. Prime Minister Naoto Kan said the situation at the Fukushima nuclear plant remained "worrisome" and that the authorities were doing their utmost to stop damage from spreading. On Sunday he said the disaster was the biggest crisis the country had faced since World War Two. The nuclear crisis was triggered by twin disasters on Friday, when the 9.0 magnitude earthquake was followed by a tsunami that ravaged Japan's north-eastern coast. More than 1,400 people were killed, but a police chief said the death toll may be over 10,000.

The International Atomic Energy Agency (IAEA) has also declared a state of emergency at the Onagawa site after excessive radiation levels were recorded there. And the cooling system pump has failed at the Tokai facility but the back-up is working, according to an official. The Japanese government is planning rolling blackouts and a limited number of trains will be running in Tokyo so energy supplies can be saved. Elsewhere, a wave of around 3m (10ft) was reported off the coast of northeast Japan by a helicopter, leading to warnings of another tsunami. Residents were ordered to flee to higher ground by Japanese soldiers after reports of a sea level change. However, the Japanese Meteorological Agency said no tsunami had been spotted and it proved to be a false alarm. Earlier a strong offshore tremor struck 150km (90 miles) northeast of Tokyo shaking tall buildings in Japan's capital, but authorities did not issue a tsunami alert. The country has suffered over 150 aftershocks since the "megaquake" hit on Friday. There is currently a warning that there is a 70% chance of another strong quake of 7.0 magnitude or over occurring.