China's manufacturing activity unexpectedly contracted in January, an official factory survey showed on Monday, its weakest since August, keeping alive calls for stimulus in the world's second-largest economy.

Policymakers have battled to reverse a post-pandemic slump driven by a crisis in the property sector, weak consumption and high government debt.

Manufacturing slowed in China in January for the first time in four months as workers began leaving assembly lines to travel to their hometowns for Lunar New Year holidays. The National Bureau of Statistics said its purchasing managers index,

China's manufacturing activity fell in January, an official factory survey showed on Monday. The official purchasing managers' index (PMI) contracted to 49.1 in January from 50.1 in December, below the 50-mark separating growth from contraction and missing a median forecast of 50.

The official purchasing managers' index for January came in at 49.1, data released by the National Bureau of Statistics on Monday showed.