The following is a list of key events since a massive earthquake and tsunami devastated northeastern Japan on Friday, March 11:

Friday, March 11:

- An undersea earthquake with a magnitude initially put at 8.9, one of the most powerful ever recorded, strikes off Japan's northeastern coast just before 3:00 pm local time. The authorities issue a tsunami warning.

- A 10-metre (33-foot) tsunami smashes over the northeastern Japanese coast, causing massive damage and flooding. A series of aftershocks follows, many exceeding magnitude 6.0.

- Japanese authorities announce that four nuclear power stations in quake-hit areas have been shut down. Eventually 11 of the nation's roughly 50 plants stop producing power.

- The US Geological Survey (USGS) says the quake was the most powerful to hit Japan since records began.

Saturday, March 12:

- The Japanese government orders the evacuation of residents living close to the Fukushima No. 1 nuclear power plant, where the disaster caused cooling systems to fail and sparked fears of a meltdown.

- An explosion occurs in a building housing one of the plant's reactors.

- Japan mobilises 100,000 military and other rescue personnel. Offers of aid pour in from around the world, including from the US military stationed in Japan.

- Video images show the extent of the damage, with the tsunami washing away houses and cars and hurling ships far inland, while fires blaze over large areas.

- USGS says the force of the quake moved Honshu -- Japan's main island -- by 2.4 metres (eight feet).

Sunday, March 13:

- The government says 230,000 people have been evacuated from the vicinity of the crippled nuclear reactors.

- The police chief in badly hit Miyagi prefecture says the number of deaths is certain to exceed 10,000 in his region alone.

- Prime Minister Naoto Kan says Japan is facing its worst crisis since the end of World War II.

- A man who was swept out to sea on a piece of the roof of his house is rescued by a naval vessel around 15 kilometres off the coast.

- The Japanese government announces energy rationing due to the shutdown of nuclear power stations. Millions of residents are without any power or water.

Monday, March 14:

- A second explosion occurs at the stricken Fukushima nuclear power station.

- Rescuers say they have found 2,000 bodies in Miyagi prefecture.

- Share prices plunge 6.18 percent on the Tokyo stock exchange.

- A United Nations humanitarian agency says 1.4 million Japanese are without running water and more than half a million have been evacuated.

- The International Atomic Energy Agency says it is 'very unlikely' Fukushima will turn into a Chernobyl-like situation.

- USGS upgrades the magnitude of Friday's quake to 9.0.

Tuesday, March 15:

- Two more blasts and a fire rock the Fukushima plant and radiation levels around the facility reach dangerous levels, prompting the government to advise people up to 30 kilometres (20 miles) from the reactor to stay indoors.

- Officials say that higher-than-normal radiation levels are detected in Tokyo.

- The official death toll from the disaster passes 2,400.

- Japan stocks fall more than 14 percent before clawing back some losses with shares ending down 10.55 percent.

- The Bank of Japan pumps eight trillion yen (almost $100 billion) into the financial system to soothe shaken money markets following a record 15-trillion yen injection Monday.

Wednesday, March 16

- A new fire erupts at the Fukushima plant. Workers are briefly evacuated, as a tall white cloud is seen billowing into the sky over the complex.

- Radiation levels at the plant's entrance spike before easing.

- Another strong 6.0-magnitude aftershock hits. Buildings in Tokyo sway.

- Emperor Akihito delivers a rare address to the nation, offering his prayers and expressing his deep concern over the escalating nuclear crisis.

- The official number of dead and missing surpasses 11,000.

- Tokyo shares rebound after the biggest two-day sell-off in 24 years. The headline Nikkei share index closed up 5.68 percent on bargain hunting.

- The Bank of Japan pumps another 3.5 trillion yen into the financial system.

Thursday, March 17

- The official number of dead and missing hits 14,650, a rise of nearly 1,000 in just a few hours.

- Foreign governments urge their citizens to leave Tokyo and US State Department authorises the voluntary departure of US embassy family members.

- Chinook helicopters dump tonnes of water in a desperate effort to cool overheating nuclear reactors.

- The government says Japan faces major blackouts unless energy use falls.

- Tokyo shares close down 1.44 percent as the central bank injects another five trillion yen ($63 billion) into its buckling financial system.

- US President Barack Obama offers to give Japan any support that it needs, the Tokyo government says.