The Hang Seng Index dropped 2.3 percent, or 597.30 points, to 25,554.02 in opening trade.

The benchmark Shanghai Composite Index opened 1.58 percent, or 44.51 points lower, at 2,776.99. The Shenzhen Composite Index, which tracks stocks on China's second exchange, dropped 1.87 percent, or 28.36 points, to open at 1,488.91.