BANGKOK, Thailand - Japan's Nikkei stock index nose-dived nearly 11 per cent Tuesday as the earthquake-shattered country faced an unfolding nuclear crisis after a radiation leak was detected at a crippled power plant and residents were warned to stay indoors. Other Asian markets also tumbled.

The benchmark Nikkei 225 stock average sank a staggering 10.6 per cent -- more than 1,000 points -- to close at 8,605.15 after hitting a midday low of 8,227.63 points, more than 14 per cent down. The broader Topix, meanwhile, lost 8 per cent.

The Nikkei's losses followed a 6 per cent tumble Monday -- the first trading day since a devastating earthquake and tsunami struck the northeastern coast, washing away towns and likely killing more than 10,000 people. Losses on Monday and Tuesday have sent the Nikkei spiraling downward 20 per cent since the beginning of the year.

Other Asian markets were sharply down because large Japanese investors such as insurance companies and hedge funds pulled money from overseas and repatriated it ahead of the mammoth job of rebuilding, according to Tom Kaan, head of equity sales at Louis Capital Markets in Hong Kong.

Investors felt the biggest shock waves when Japan's Prime Minister Naoto Kan announced that radioactive material had leaked from the Fukushima Dai-ichi nuclear plant in Fukushima province and that more leaks were possible.

"There is also fear of contamination. We've never had three nuclear power plants blowing up one after the other," Kaan said. "When you have a situation like that, everyone takes to the extreme of being conservative. How far will it affect the air that we breath and how far the contamination will go? Is it going to reach Korea or China? That's anyone's guess."

Kaan said the Middle East crisis was still far from over and had the potential to further damage markets, oil prices, and the global economic recovery -- especially if the political turmoil and violence that has hit countries like Egypt and Libya spreads to oil powerhouse Saudi Arabia.

The stock sell-off in Tokyo hit nearly every business sector, with electric companies under intense pressure again. The Tokyo Electric Power Co., which operates the crippled nuclear plant, crashed 24.7 per cent. Toshiba Corp., a maker of nuclear power plants, sagged 19.5 per cent.

Other companies with nuclear power-related businesses faced a second day of free-falling losses. Mitsubishi Heavy Industries tumbled 10.9 per cent, Kobe Steel Ltd. dived 12.1 per cent, and Hitachi Ltd. shed 12.6 per cent. Cosmo Oil, whose refinery caught fire after the quake, slid by 9 per cent.

Car makers declined partly because quake-stricken northeastern Japan is a major centre for auto production, complete with a myriad of parts suppliers and a network of roads and ports for efficient distribution.

Toyota Motor Corp. said it would suspend manufacturing at its domestic plants through Wednesday -- a production loss of 40,000 cars. Other manufacturers like Sony Corp. and Honda Motor Co. were also forced to halt production. Damage to roads and distribution system made it all but impossible to move products.

Toyota, the world's largest automaker, fell 7.4 per cent. Honda lost 3.9 per cent and Nissan Motor Corp. dropped 3.3 per cent. Mitsubishi Motors Corp. lost 9.3 per cent and truck-maker Isuzu Motors Ltd. plunged 9.2 per cent.

High-tech suppliers like Elpida Memory Inc., the world's No. 3 maker of computer-memory chips and a leading manufacturer of DRAM, slid 9.7 per cent.

Ports were closed, steel plants stopped producing, and the country was being urged to conserve power. With manufacturing all but paralyzed, exporters were also hammered -- Panasonic Corp. was down 11.2 per cent, Sharp Corp. slid 8.5 per cent, and Sony Corp. lost 8.9 per cent.

Fears about the safety of nuclear power weighed on the shares of companies involved in uranium mining. Energy Resources of Australia Ltd., one of the world's largest uranium producers, fell 14.3 per cent in Sydney.

Even the rare stocks that did well Monday -- industrial and materials companies, which gained due to expectations that they would benefit when Japan rebuilds -- tumbled Tuesday.

Japanese construction company Kajima Corp. dropped 13.1 per cent and Nishimatsu Construction Co. Ltd. skidded 23.5 per cent. Analysts said that while the Japanese economy remained virtually shut down, companies in China and elsewhere could fill the void.

Elsewhere in Asia, South Korea's Kospi was down 2.4 per cent to 1,923.92, and Australia's S&P/ASX 200 fell 2.1 per cent to 4,528.70. Hong Kong's Hang Seng index slumped 3.3 per cent to 22,568.28, and mainland China's Shanghai Composite Index lost 2 per cent to 2,879.09.

On Wall Street Monday, concerns over the economic impact of the earthquake and tsunami in Japan led to a broad sell-off. The Dow Jones industrial average lost 51.24, or 0.4 per cent, to 11,993.16.

The broader S&P index fell 7.89 points, or 0.6 per cent, to 1,296.39. Nine out of the 10 sectors that make up the Standard and Poor's 500 index lost ground. Utilities companies fell 1.4 per cent, the most of any group.

The Nasdaq composite dipped 14.64, or 0.5 per cent, to 2,700.97.

Benchmark crude for April delivery dropped $1.99 to $99.20 a barrel in electronic trading on the New York Mercantile exchange. The contract added 3 cents to settle at $101.19 on Monday.

The dollar was worth 81.79 Japanese yen Tuesday, down from 81.88 yen late Friday. A major natural disaster like an earthquake can bolster the yen because investors expect the Japanese public and insurance companies to buy back their home currency in order to fund the country's reconstruction, increasing demand for the yen.

The euro fell to $1.3940 from $1.3995.