JOIN USPlumes of white smoke were seen coming from the Fukushima plant Monday after a loud explosion at its No.3 reactor, the Nuclear and Industrial Safety Agency (JNISA) said.
Tokyo Electric Power Co. said 11 people were injured and seven others were missing after the blast. One of the walls of the reactor building collapsed.
The likelihood of high levels of radiation in the area is low, the agency noted, but warned the 600 people who were still in the 20-km evacuation zone to leave immediately.
The agency said large amounts of hydrogen have amassed in the upper parts of the reactor building, where the pressure remained unusually high, similar to that of the No.1 reactor building that exploded Saturday.
Cooling operations at the reactor were continuing although the coolant levels were low, the JNISA said. It added that the containment vessel in the reactor is still intact.
Speaking at a press conference Monday, chief cabinet secretary Yukio Edano said the explosion did not damage the reactor and the containment vessel and that there was little possibility of mass radiation being leaked into the air.
Edano expressed concern Sunday that a hydrogen explosion could occur at the plant's No.3 reactor -- the latest reactor to face a possible meltdown, following a hydrogen blast Saturday in the plant's No. 1 unit.
Commercial operation of Fukushima's first nuclear reactor (Fukushima I-1) started in 1971, while the most recent one (Fukushima II-4) started in 1987.
While struggling to avert a nuclear meltdown, the government is also striving to take care of millions of survivors who are still without drinking water, electricity and proper food after Friday's catastrophic magnitude-9 earthquake and ensuing massive tsunamis.
About 2,000 bodies were found Monday on two shores in Japan's Miyagi prefecture, the Kyodo News said. The toll is likely to rise significantly.
Earlier, the National Police Agency had confirmed the death of more than 1,600 people.
While the country is grappling with the widespread damage, countries around the world have offered help to Japan in dealing with the aftermath of the devastating earthquake.
At least 50 countries and regions have promised to provide relief support.
A 15-member Chinese rescue team, which arrived in Japan Sunday, was set to start search and rescue operations Monday in Ofunato city in the northeastern Iwate prefecture.
China also pledged 30 million yuan (about $4.5 million) worth of emergency humanitarian assistance to Japan to help the disaster relief there, the Chinese commerce ministry said Monday.