Asian shares started August lower as disappointing economic data from China weighed on investors' confidence.
A private survey showed contraction in China's vast manufacturing sector on Monday. It followed the release of official data over the weekend and added to concerns about the slowing of world's second largest economy.
Both surveys showed that factory activity dropped in July.
The Shanghai Composite index was down 2.5% to 3,572.29 in afternoon trade.
US based hedge fund Citadel also confirmed that trading in one of the accounts it manages in Shenzhen has been restricted by China's securities regulator.
The regulator has restricted trading in 34 stock accounts for suspected trading irregularities, including abnormal bids for shares and bid cancellations that might have affected the recent slump in the market.
Meanwhile, Hong Kong's Hang Seng index was down by 1% to 24,381.67 points.
Shares of HSBC outperformed the index, up 1.2%, after it reported a 10% increase in pre-tax profit in the first half of year from a year ago.
Weak US data
Poor US wage growth data from Friday also darkened the mood as labour costs in the second quarter recorded their smallest increase in 33 years.
Japan's benchmark Nikkei 225 index ended down 0.2% at 20,548.11, while Australia's ASX/200 finished lower by 0.4% to 5,679.30 points.
South Korean shares were lower despite data showing that the current account surplus in June hit a record high as exports surged, while imports fell.
The seasonally adjusted current account surplus rose to a preliminary $10.8bn from a revised $6.4bn in May.
Exports were up 8.8% from a month ago, while imports fell 3%.
The Kospi index closed down 1.1% to 2,008.49 points.
Source: BBC