The Tokyo Stock Exchange tumbled Friday, driving the benchmark Nikkei index to a 20-year closing low on growing fears that a military strike will be launched on Iraq.

The 225-issue Nikkei average slid 225.03 points, or 2.69 percent, to close at 8,144.12, its lowest finish since March 15, 1983, when it ended at 8,111.83.

It was the fourth straight session the key index closed lower.