Asia shares join global losses on weak data; ECB watched

Asian stocks dropped on Thursday following weak global data and continued unrest in Hong Kong, while investors awaited the European Central Bank's policy meeting.

U.S. benchmark indices skidded over 1 percent overnight, posting their worst beginning to October since 2011, after manufacturing activity and construction spending declined in August. In Europe, Markit's final manufacturing Purchasing Managers' Index (PMI)hit a 14-month low with Germany's manufacturing sector contracting for the first time in 15 months.

"The next 30 trading days feels like mid-2012 – just before the 'whatever it takes' rally that drove global markets to record highs. It also feels distinctly like early 2011, when there were jitters around China and the eurozone crisis. The trading reactions in the U.S. markets illustrate that risk assets are living on borrowed time," said Evan Lucas, market strategist at IG.

Read MoreStocks got slammed but can they snap back?

The European Central Bank (ECB) is widely expected to leave interest rates unchanged at its policy review later today. Attention will be on the bank's plan to purchase asset-backed securities (ABS), first announced last month. Traders expect the ECB to buy a total of 200 billion euros, according to a Reuters poll.

ASX 200
CNBC 100

Hong Kong in focus

Hong Kong's pro-democracy rally extended into its seventh day. The city's chief executive, Leung Chun-ying, is reportedly willing to let protests continue for weeks if necessary. The city's markets are closed until Friday, while markets in Shanghai are shut until October 7 for China's national day holiday.

Read MoreGlobal solidarity for Hong Kong swells

U.S. Secretary of state John Kerry called on officials in China and Hong Kong to exercise restraint in dealing with the demonstrators. In response, Chinese foreign minister Wang Yi said the protests are a domestic issue and that countries should respect China's sovereignty.

Nikkei 2.6% lower

Japan's benchmark Nikkei dropped to a one-month closing low, extending losses into a fourth session, as the yen moved further away from a six-year low of 110 per dollar.

Read MoreWhy the dollar-yen rally will fizzle soon

Japan Airlines and All Nippon Airways shed over 4 percent each, tracking losses in U.S. airlines after the first case of Ebola was diagnosed in the U.S.

Honda Motor tanked 4 percent on the back of disappointing domestic sales in the first-half and reports the firm may be scaling back production in Japan.

ASX down 0.7%

Australia's benchmark S&P ASX 200 fell as investors digested mixed data. The country's trade deficit widened to A$787 million in August, larger than estimates, while August home building approvals posted their biggest monthly gain since May.

The 'Big Four' banks fell on profit-taking following two sessions of strong gains; Australia New Zealand Banking led losses by nearly 1 percent.

Reservation website finished nearly 7 percent higher after regulators approved Expedia's acquisition of the firm.

Kospi drops 0.8%

South Korean stocks ended at their lowest levels since June 23, extending losses into a sixth straight day. The benchmark Kospi slightly pared losses after regulators said new measures to revitalize the stock market will be announced later this month.

Hyundai Motor tumbled 4.5 percent after the company's workers voted in favor of a wage deal, ending weeks of strikes.