"Fears of (People's Bank of China) de-leveraging could trigger the correction of China equities, and discourage capital inflow for China stock markets," said Mizuho's chief Asian FX strategist Ken Cheung.
On the mainland, the CSI300 index fell 0.4%, to 5,496.97 points at the end of the morning session, while the Shanghai Composite Index was unchanged at 3,596.10 points.