Hong Kong equities fell the most since November, dragged lower by technology stocks such as Galaxy Entertainment and Tencent Holdings.
Tech rout comes just days after the world's fourth-largest equity market witnessed a small-cap selloff, which wiped out more than $6 billion in market value.
While Hong Kong's benchmark index is among the best performers this year, gaining about 15 percent till date, sudden slumps in stock prices have left investors worrying.
Sentiment across Asia was mixed while safe haven assets such as the yen and gold strengthened after North Korea test-fired an intermediate-range ballistic missile toward Japan.
At 0615 GMT, the benchmark Hang Seng Index fell 1.59 percent or 410 points to 25,373. It dropped as much as 2.1 percent earlier in the session.
Galaxy sank the most on the gauge, plunging 5 percent, while Tencent headed for its biggest loss since February 2016.
Other laggards included China Shenhua Energy down 3.3 percent, Geely Automobile Holdings dropped 3.1 percent while Want Want China Holdings lost 3 percent.
Volume in Hang Seng Index futures was 65 percent higher than the five-day average.
