Following are the main developments after a massive earthquake and tsunami devastated northeast Japan and crippled a nuclear power station, raising the risk of uncontrolled radiation.
- Engineers successfully attach a power cable to the outside of the damaged Fukushima nuclear plant in a first step to help cool reactors and stop the spread of radiation.
- Further cabling inside under way before an attempt to restart water pumps to cool overheated fuel rods. Once power is restored, the next stage will be to check equipment is working and not damaged before trying to crank up the coolers at reactor 2, followed by 1, 3 and 4.
- IAEA says its remains unclear whether water pumps will work.
- Japan government spokesman says some stabilisation at the stricken No.3 reactor. Engineers meanwhile are using diesel generators for less critical reactors No 5 and No 6 reactors.
- Tests detect radiation above the national safety level in spinach and milk produced near the Fukushima plant. A sample of tap water from Tokyo shows a tiny level of radioactivity.
- IAEA says Japan considering whether to halt sale of food products from Fukushima prefecture and radioactive iodine in food can pose short-term risk to human health.
- The UN's atomic agency says conditions at the plant are grave but not deteriorating badly.
- If engineers are unable to cool the reactor, the last option would be entombing the plant with concrete and sand to prevent a catastrophic radiation leak, the method used at Chernobyl in Ukraine in 1986.
- Severity rating of the nuclear crisis raised to level 5 from 4 on the seven-level INES international scale, putting it on a par with the Three Mile Island accident in 1979. Chernobyl was a 7 on that scale.
- A report about a man pulled alive from the rubble of a house eight days after the quake turns out to be false. The man had been in an evacuation centre and returned to his ruined house when he was discovered by rescue workers.
- Nearly 7,000 people have been confirmed killed in the quake and tsunami. Another 10,700 people are missing with many feared dead.
- Prime minister Nakato Kan tried, and failed, to form a crisis cabinet following the earthquake and tsunami. The opposition, including the Liberal Democratic Party, told Kan it rejected his idea of increasing the number of cabinet ministers to create new posts to handle reconstruction policy.