Death toll expected to exceed 10,000 from the quake and tsunami, public broadcaster NHK says. About 2,000 bodies found on two shores of Miyagi prefecture, Kyodo news agency reports.
Japan is battling to prevent a nuclear catastrophe. A hydrogen explosion jolts the No. 3 reactor of the Fukushima Daiichi nuclear power plant, 240 km (150 miles) north of Tokyo. Operator Tokyo Electric Power Company (TEPCO) says 11 people were injured.
Before the blast, officials said 22 people had suffered radiation contamination. Up to 190 may have been exposed.
TEPCO, says nuclear fuel rods at the quake-striken reactor are exposed again and overheating, raising the risk of them melting.
United States says Japan asked for additional equipment to help coool reactors.
International Atomic Energy Agency said that the crisis is unlikely to turn into another Chernobyl.
Switzerland's energy minister said the country has suspended approvals process for three nuclear power stations so safety standards can be revisited.
Germany's Chancellor Angela Merkel said nuclear plants that had been scheduled to close in the next three months, before an extension deal was struck, will not shut down after all.
Meanwhile, authorities have set up a 20-km (12-mile) exclusion zone around the Fukushima Daiichi plant and a 10-km (6 mile) zone around Fukushima Daini.
Strong aftershocks persisted in the stricken area.
About 450,000 people evacuated nationwide in addition to 80,000 from the exclusion zone around the nuclear power plants. Almost 2 million households are without power in the freezing north and about 1.4 million households have no running water.
Reactor operator said rolling blackout will affect 3 million customers, including large factories, buildings and households. According to the reactor operator, blackouts affected 113,000 households on Monday.
Japan's Nikkei share index falls more than 6 percent, dragging European stocks to their lowest in three months.
The Bank of Japan (BoJ) offered to pump a record $85 billion into the banking system.
Credit Suisse estimates the loss at between 14 trillion yen ($171 billion) and 15 trillion yen just to the quake region.