Tokyo, Japan (BBN)-Shares in Asia were down on Thursday following US markets which closed lower after Federal Reserve chair Janet Yellen expressed concerns over the valuations of US shares.

She said current valuations were “quite high”, but added she didn’t see any bubbles forming, reports BBC.

Japan’s Nikkei was down 1.22% at 19,293.26 points after being closed all week for a holiday.

Australia’s benchmark S&P/ASX 200 index was down 0.79% at 5,647.20 points.

Shares in Australia saw their biggest one-day fall in more than two years on Wednesday following some worrying results from Australia’s biggest banks.

Investors are concerned about the country’s big four banks facing slower growth.

National Australia Bank (NAB), the last of the big banks to announce their results this week, posted a 5.4% rise in cash profit year-on-year for the six months to March.

It also announced a 5.5bn Australian dollar ($4.4bn; £2.8bn) capital-raising exercise which will involve the selling of new shares.

NAB wants to demerge and float its troubled British bank, Clydesdale, and shore up its balance sheet.

The lender’s capital-raising announcement has been reported by some of Australia’s media as being the largest in the country’s corporate history.

In China, Hong Kong’s Hang Seng index was down 0.5% at 27,501.63, while the Shanghai Composite was down 0.42% at 4,211.63.

Both benchmark indexes also finished lower on Wednesday.

Several companies on the mainland announced share offerings to investors through the week, which pulled funds from other stocks.

Elsewhere, South Korea’s benchmark Kospi index was down 1.24% at 2,078.55 points, following the US trend.