Japan's stock market retreated Thursday after bouncing back a day earlier from major losses linked to the earthquake, tsunami, and problems at Japanese nuclear power plants.
Investors sent Tokyo's Nikkei index down 1.4 percent, as the yen hit record highs against the U.S. dollar.
Japanese finance officials said market speculation is responsible for the surge, with talks of Japanese insurance companies and other firms needing yen to pay for reconstruction efforts.
The Japanese government pumped another $76 billion into the financial system Thursday in a bid to reassure markets.
Finance ministers from the Group of Seven industrialized nations are set to discuss currency issues on Friday.
The Nikkei had rallied on Wednesday, surging 5.7 percent to recover almost a third of the ground lost earlier this week.
Global markets did not follow the Nikkei's rally Wednesday, as continuing concerns about the situation in Japan pushed markets in the United States and Europe significantly lower.
Reuters reports the damage to the world's third-largest economy could go as high as $200 billion, including the costs of rebuilding and disruptions to business and factory output.
Japanese car makers stopped production immediately after last Friday's earthquake. Most factories were undamaged by the quake and tsunami, but are now hampered by shortages of electricity and parts, and difficulties many workers face getting to the job.
A few factories are resuming production, particularly those that supply parts or tires needed by Japanese and foreign plants to resume production.
Several car companies say they may keep most of their factories closed until at least March 20. The Bloomberg financial news service reports that Toyota will lose about $80 million in profit for each day of lost output.
In the meantime, the government is urging citizens to conserve electricity. The plea brought unaccustomed darkness to Tokyo's Ginza area, famous for advertising and displays that light up the night.
Some information for this report was provided by AFP.