A container port in Qingdao in east China's Shandong province.

China's exports posted their lowest growth rate in almost a year in May while imports unexpectedly fell, government data showed on Saturday, underlining concerns that growth in the world's second-largest economy could slow anew in the second quarter.

Evidence has mounted in recent weeks that the economy is fast losing growth momentum as sluggish domestic demand fails to make up for lethargic export sales.