The Hang Seng Index fell 424.53 points to 27,656.68 by the break on turnover of HK$94.65 billion (US$12.21 billion).
The benchmark Shanghai Composite Index fell 1.40 percent, or 69.25 points, to 4,872.46.
The Shenzhen Composite Index, which tracks stocks on China's second exchange, lost 1.04 percent, or 30.32 points, to 2,887.70.