Activity in China's manufacturing sector has unexpectedly improved in August.

The official Purchasing Managers' Index rose to 50.4, compared with the previous month's 49.9. Any mark above 50.0 indicates expansion.

The official non-manufacturing PMI stood at 53.5 in August, compared to the previous month's reading of 53.9. China's continuing growth in services offsets persistent weakness in manufacturing and exports that drag down the world's second-largest economy.