China's exports fell by 8.8% in August year-on-year, while imports contracted 7.3%, customs data showed on Thursday, increasing pressure on the country's vast manufacturing sector as demand sags at home and abroad.

A Reuters poll of economists had forecast a fall of 9.2% in exports and a drop of 9.0% in imports.

The world's second-largest economy risks missing Beijing's annual growth target of about 5% as officials wrestle with a worsening property slump, weak consumer spending and tumbling credit growth, leading analysts to downgrade growth forecasts for the year.

Beijing has announced a series of measures in recent months to shore up growth, with the easing of some borrowing rules last week by the central bank and the top financial regulator to aid homebuyers.

But analysts warn the steps may have little impact with a labor market recovery slowing and house income expectations uncertain.

Chinese factory activity shrank for a fifth straight month in August, a purchasing managers' index showed last week, weighed down by a lack of new export orders and imported parts.

However, factory owners indicated producer prices had improved for the first time in seven months, in a nod to improving domestic demand.

South Korean shipments to China, a leading indicator of the latter's imports, dropped just a fifth last month, softening from a decrease of 27.5% a month earlier.

China posted a trade surplus of $68.36 billion in August, compared with a forecast $73.80 billion and a July figure of $80.6 billion.