TOKYO -- Japan's benchmark Nikkei Stock Average plunged temporarily 1,300 points or more than 3% from the previous day in the Tokyo morning trading, continuing the downward trend in high-tech stocks in the U.S. stock market. Concerns over the situation in the Middle East have also spurred risk aversion selling.

The Nikkei 225 index fell below the 37,000 mark during trading hours for the first time in two and a half months, as selling in value-laden semiconductor-related stocks swelled in Tokyo. Major chip-related stocks such as Tokyo Electron, Screen Holdings and Lasertec all fell temporarily by more than 7%.