The was down about 3.8 percent at 29,306.63 at 11.08 a.m. HK/SIN while the was down 4.5 percent at 3,114.0472.
Despite the sell-off, equities may just be in their "first leg of correction," said William Ma, chief investment officer of Noah Holdings in Hong Kong.
Even though the mainland market is not fully connected to the global market, fund managers on the mainland are talking about the global economy "half the time," underscoring the international nature of markets that is causing a "synchronized collapse" in both Hong Kong and China, Ma told CNBC.
With everything happening, it's still too early to jump into the market for bargains, he said.
Even amid the sharp slide, some experts recommended calm.
One, Philip Li, senior fund manager at Value Partners, said the current market downturn appears to be technical in nature.
Asia will be under pressure as long as its markets are correlated to the Dow, but earnings expectations for companies and the growth outlooks for regional economies are solid, so the current rout appears divorced from any fundamentals, Li added.
The Chinese markets were already under pressure even before this week's market sell-off as investors took profit ahead of the long Lunar New Year public holidays that start later next week.