Asian equities and the euro tumbled Monday on fears Greece will crash out of the eurozone after Athens called off debt reform talks and announced a referendum on creditors' proposals next weekend, days after a repayment deadline.
Markets in mainland China were again volatile after plunging about 20 percent from their recent peaks over the past two weeks, with a central bank interest rate cut at the weekend playing off against the crisis in Greece and profit-taking.
Tokyo sank 1.78 percent by lunch, Sydney shed 1.81 percent, Seoul lost 1.45 percent and Taipei was 1.90 percent lower.
Hong Kong tumbled 1.76 percent, but Shanghai added 0.32 percent.
The mainland Chinese market is swinging wildly, opening 2.31 percent higher before retreating one point to 0.20 percent in mid-morning trade, then pushing back into positive territory.
Greek Prime Minister Alexis Tsipras at the weekend stunned world markets when he announced the national poll for July 5 in which voters will be asked to decide on creditors' reform proposals, as five months of talks failed to find common ground.
The EU and IMF responded by rejecting a request to extend Greece's bailout beyond its June 30 expiry date, meaning it will default on a key payment and possibly crash out of the eurozone.
Tsipras has now imposed capital controls throughout the country to avoid flight of cash, with banks closed until July 6 and ATM withdrawals limited to 60 euros a day.
Speaking on national television on Sunday evening, Tsipras said the Bank of Greece had recommended a "bank holiday and restriction of bank withdrawals" after the European Central Bank said it would not increase its financial support to Greek lenders, despite early signs of a chaotic bank run.
- Euro takes hit -
The euro tumbled to $1.1000 and 135.57 yen in Asian trade, from $1.1160 and 138.26 yen in New York at the end of last week.
The dollar was at 123.15 yen against 123.89 yen in US trade, with investors rushing to safer investments.
"In the face of pressure from the eurozone to accept austerity measures, the Greeks answered that it's hard to live just on water," Mitsuo Shimizu, deputy general manager at Japan Asia Securities Group Ltd in Tokyo, told Bloomberg News.
"Carrying out a referendum buys the Greek side some time. Digesting the worst-possible scenario of a Greek default, global stock markets could fall 1 to 2 percent today."
Chinese traders were swinging from black to red after Saturday's move by the People's Bank of China to cut rates and lower the amount of cash lenders must keep in reserve.
Analysts say the announcement was in response to dramatic stock market falls over the previous two weeks.
Shanghai dived more than seven percent Friday -- and 18.8 percent in the two weeks from peaking on June 12 -- as authorities tighten rules on margin trading, while dealers are also worries about stocks' high valuations.
"The cut of interest rate and reserve requirement in the weekend is the main factor that affects the stock market today," Zhang Yanbing, an analyst from Zheshang Securities, told AFP.
"The policy is a good one, but the prospect is still not certain yet. Some investors that bore losses last week may also start to sell. So the trend may still be a bit volatile. We need to wait and see."
Oil prices were lower. US benchmark West Texas Intermediate for August delivery was down 86 cents to Sg$58.77, while Brent crude for August eased 78 cents to $62.48.
Gold fetched $1,183.01 compared with $1,174.05 late Friday.