The crisis in Ukraine prompted investors in Tokyo to unload shares on Thursday, with the benchmark index ending the day sharply lower.

The selloff accelerated after Russian President Vladimir Putin said his country would carry out "a special military operation" in eastern Ukraine.

The Nikkei Average closed below the 26,000 mark for the first time in a year and three months.

The index finished at 25,970, down 478 points or 1.8 percent, from Tuesday's close. Wednesday was a national holiday in Japan. Traders sold shares almost across the board.

The Nikkei 225 extended its losing streak for a fifth trading day. It has shed 5.4 percent over the period.

Gold prices in Japan are rising, along with demand for haven assets. Benchmark gold futures traded above 7,100 yen, or 62 dollars, a gram on Thursday on the Osaka Exchange. That is the highest ever for the index.