Mainland Chinese shares continued to head lower today, leading the rest of Asia down as concerns over the market's steep slide spread. The benchmark Shanghai Composite was down 3.6 per cent to 3,380.31 points despite aggressive measures by regulators such as banning big investors from selling stocks to boost the flagging market. Chinese shares have lost more than 30 per cent of their value in the past month.Hong Kong's Hang Seng index was down 0.5 per cent to 23,369.23 in early trade. The Chinese government continued to roll out more measures today by trying to ease margin loan requirements.