Mainland Chinese shares extended losses in a volatile session, following Monday's suspension of trading which led to a global equities sell-off.
Hong Kong's Hang Seng index also fluctuated through the day, and ended 0.7% lower at 21,188.72.
Trading in Shanghai was suspended early on Monday under a new rule designed to limit dramatic falls in markets.
But regulators said on Tuesday they may restrict stock sales to stem falls.
The China Securities Regulatory Commission said it would consider restricting the proportion of shares that major shareholders could sell during a given period of time.
The central bank also injected an unexpected 130bn yuan (£13.55bn; $19.94bn) into the market to keep borrowing costs down - in a move to reassure retail investors.
The measures, however, did little to prevent Chinese shares from falling in afternoon trade.
