(AFP) - okyo's benchmark index plunged more than two percent on Friday after European and US stocks suffered big drops as volatility continued to dog equity markets.

The Nikkei index fell 2.32 percent, or 508.24 points, to close at 21,382.62. Over the week, it lost 8.13 percent.

The broader Topix index was down 1.91 percent, or 33.72 points, at 1,731.97, leaving it down 7.09 percent over the week.

"Unless US stocks settle, it's hard to change market sentiment," said Hikaru Sato, senior technical analyst at Daiwa Securities.

"Uncertainty is likely to continue for now as the market may need about a month to adjust itself," Sato told AFP.

Yoshihiro Ito, chief strategist at Okasan Online Securities, said in a commentary: "Investors are discouraged by a higher yen and plunges in European and US stocks." 

But Kyoko Amemiya, senior market advisor at SBI Securities, said the drops presented an opportunity for investors.

"Falls in Japanese shares certainly reflect drops in US shares, but there is no fundamental change in Japanese corporate performances," she told AFP.

"That means there is now a chance to buy on dips in companies with brisk earnings," she added.

The dollar fetched 108.90 yen in Tokyo afternoon trade, up slightly from 108.74 in New York but down from 109.61 yen in Tokyo Thursday.

Overnight on Thursday, the three major US indices plunged, with the Dow Jones Industrial Average plummeting 4.2 percent to 23,860.46.

The broad-based S&P 500 sank 3.8 percent and the tech-rich Nasdaq Composite Index dived 3.9 percent.

In Tokyo, Nissan dropped 3.09 percent to 1,127.5 yen after the Japanese car giant slashed its forecast for full-year operating profit.

Its rival Toyota was down 1.13 percent at 7,465 yen.

Sony lost 2.74 percent to 5,174 yen while Panasonic down 1.36 percent at 1,585 yen.

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