(Reuters) - Following are main developments after a massive earthquake struck northeast Japan on Friday and set off a tsunami.



- 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 battles to prevent 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) (9501.T) says 11 people were injured.

- Chief Cabinet Secretary Yukio Edano says the core container at the reactor is intact and the explosion is unlikely to have produced a large escape of radioactivity.

- Before the blast, officials said 22 people had suffered radiation contamination. Up to 190 may have been exposed.

- Experts pursue efforts to cool down three reactors at the Fukushima Daiichi plant. Experts say the use of seawater in this operation is unprecedented.

- Nuclear safety agency rates the incident a 4 on the 1 to 7 International Nuclear and Radiological Event Scale, less serious than Three Mile Island, a 5, and Chernobyl at 7.

- U.S. warships and planes helping relief efforts have moved away from Japan's Pacific coast temporarily because of low-level radiation.

- 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 persist 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 says rolling blackout to affect 3 million customers, including large factories, buildings and households.

* Japan's Nikkei share index falls more than 6 percent, dragging European stocks to their lowest in three months.

- The Bank of Japan (BoJ) offers to pump a record $85 billion into the banking system.

- Credit Suisse estimates the loss at between 14 trillion yen and 15 trillion yen just to the quake region.

(Tokyo bureau; World Desk Asia)