A key manufacturing index in China fell below the 50-point mark that separates growth from contraction in April for the first time in four months.

The National Bureau of Statistics says the Purchasing Managers' Index for manufacturing stood at 49.2, down 2.7 points from March. The PMI is based on a survey of 3,200 companies.

The decline is due to subdued demand both at home and abroad, as the property sector, one of China's main industries, remains sluggish, and orders for exports have fallen amid prolonged inflation and interest rate hikes overseas.

The index for the non-manufacturing sector, which includes the service industry, was down 1.8 points from last month. But at 56.4, it remained above the 50-mark for the fourth straight month.

Sectors such as transport and hotels remain strong after the country ended its "zero-COVID" policy.

Bureau officials say the manufacturing PMI fell below the 50-mark this month, partly because China's economy grew at a faster-than-expected pace in the three-month period through March.