China's factory activity shrank for the third straight month in December and at the sharpest pace in nearly three years as COVID infections swept through production lines across the country after Beijing's abrupt reversal of anti-virus measures.

The official purchasing managers' index (PMI) fell to 47.0 from 48.0 in November, the National Bureau of Statistics (NBS) said on Saturday. Economists in a Reuters poll had expected the PMI to come in at 48.0. The 50-point mark separates contraction from growth on a monthly basis.