China's export growth slowed significantly in August, customs authorities said Wednesday, as economic uncertainty is exacerbated by strict COVID-19 lockdowns across the country.

Last month, China's exports expanded 7.1 percent year-on-year, down from 18 percent growth in July, China's General Administration of Customs said, while imports were up only 0.3 percent, compared with a 2.3 percent rise in July.

Analysts surveyed by Bloomberg forecast export growth of 13 percent and a 1.1 percent increase in imports.

The slowdown in trade comes as global demand for Chinese products weakens with energy prices soaring and the United States facing the threat of recession.

Sporadic COVID-19 lockdowns around China have also dampened consumer enthusiasm and business confidence, while searing temperatures across large parts of the country this summer prompted power rationing for factories.

China's factory activity shrank for the second month in a row in August, but officials are showing few signs of relaxing strict pandemic curbs, with southwestern megacity Chengdu locking down its 21 million inhabitants last week.