Asian shares were mixed Tuesday morning with Tokyo buoyed by a weak yen but falling commodity prices raised fears about global growth as Chinese stocks slipped after a brief reprieve in their month-long rout.
Tokyo's benchmark Nikkei 225 index rose 0.43 percent, Hong Kong was up 0.23 percent, Seoul was flat, Sydney gained 0.14 percent, while Singapore edged down 0.06 percent.
Chinese shares fell sharply at the open as investors grew cautious after the market approached the key 4,000-point level, dealers said.
The benchmark Shanghai Composite Index dropped 1.64 percent while the Shenzhen Composite Index, which tracks stocks on China's second exchange, lost 1.91 percent.
Both indices moved back into positive territory in later trading.
The fresh volatility comes after Beijing launched a series of initiatives to staunch a bloodletting that saw a 30 percent plunge in Shanghai and trillions wiped off valuations.
Among the measures were a police crackdown on short-selling and a ban on big shareholders and company executives from selling stock for six months, adding to earlier announcements.
Meanwhile, dealers said a drop in commodities prices raised concerns about the global economy as crude oil briefly fell below $50 a barrel on Tuesday, and gold traded near a five-year low.
"This commodities rout is a very big concern,” Michael McCarthy, a chief strategist at CMC Markets in Sydney, told Bloomberg News.
"There's risk for a further downside. It looks like the overall global growth outlook is continuing to slow."
Investors were also keeping an eye on Greece where the government hiked taxes and paid billions of euros to its creditors on Monday, as banks reopened just days after the debt-laden country reached a bailout deal with its creditors.
In currency markets, the dollar was trading around a five-week high at 124.34 yen, against 124.30 yen in New York on Monday.
The euro bought $1.0825 and 134.61 yen, little changed from $1.0824 and 134.55 yen in US trading.
"The weaker yen and cheaper oil will have a positive effect on Japanese stocks," said Toshihiko Matsuno, chief strategist at SMBC Friend Securities Co. in Tokyo.
Eyes are now on Washington as the Federal Reserve considers when to hike interest rates from their record lows as the US economy gets back up to speed.
Last week Fed chief Janet Yellen said she saw a rise taking place before 2016 -- a rate hike is a plus for the dollar.
Meanwhile, the Bank of Japan and European Central Bank are spending hundreds of billions of dollars on bonds and other assets to support their respective economies, pushing down the value of the yen and euro.
On oil markets, US benchmark West Texas Intermediate for August delivery was down 10 cents to $50.05, after briefly dipping to $49.94, and Brent crude for September fell eight cents to $56.57 a barrel in morning Asian trade.
Gold fetched $1,103.54 after falling as low as $1,072 per ounce in Asia trade Monday.