TOKYO (Kyodo) -- Tokyo stocks fell Thursday, with the Nikkei stock index briefly losing more than 2 percent and giving up much of the previous day's gains as rising crude oil prices amid growing tensions in the Middle East triggered a broad sell-off.

The 225-issue Nikkei Stock Average ended down 931.44 points, or 1.36 percent, from Wednesday at 67,470.69. The broader Topix index finished 44.35 points, or 1.11 percent, lower at 3,951.85.

On the top-tier Prime Market, the main decliners were information and communication, nonferrous metal and oil and coal product issues.

The U.S. dollar weakened into the upper 159 yen range at one point in Tokyo following a report that the Bank of Japan will raise its key interest rate by 0.25 percentage point to 1 percent at its next monetary policy meeting later this month.

At 5 p.m., the dollar fetched 159.89-91 yen compared with 160.04-14 yen in New York and 159.70-71 yen in Tokyo at 5 p.m. Wednesday.

The euro was quoted at $1.1604-1605 and 185.54-58 yen against $1.1593-1603 and 185.61-71 yen in New York and $1.1615-1616 and 185.50-54 yen in Tokyo late Wednesday afternoon.

The yield on the benchmark 10-year Japanese government bond ended up 0.030 percentage point from Wednesday's close at 2.670 percent, as the debt was sold on weaker-than-expected demand for long-term bonds offered in a Finance Ministry auction aimed at improving market liquidity of those issues.

Investor sentiment in the stock market was dampened by reports of exchanges of attacks between the United States and Iran and Iranian strikes against Kuwait and Bahrain, reducing hopes for an early end to the war.

The rise in benchmark West Texas Intermediate crude oil futures overnight is also weighing on sentiment, brokers said.

Recent gainers among heavyweight technology shares led the day's declines, including SoftBank Group, which lost over 11 percent.

"(Investors) appear to be adjusting their positions amid concerns over short-term overheating, while confidence in AI market expansion remains intact," said Wataru Akiyama, strategist at Nomura Securities Co.'s Investment Content Department.