China's industrial output slowed in October, official data showed, as authorities fight smog by clamping down on pollution produced by heavy industries. 

Output at factories and workshops expanded 6.2% year-on-year, the National Bureau of Statistics (NBS) said, slowing from 6.6% in September and below a forecast of 6.3%. 

The government has moved to wind down production at some steel factories and smelters in a drive to clean up the country's smog-ridden cities. 

Factories also closed during last month's Communist Party congress, during which President Xi Jinping called for more efforts to protect the environment. 

The government is also pushing to make domestic demand a growth driver of the world's second largest economy and make China less reliant on manufacturing and exports. 

"Generally speaking, the national economy maintained stable performance with improved quality and sound momentum," NBS spokeswoman Liu Aihua told reporters. 

"However, we must be aware that China is at a pivotal stage for transforming the growth model," she said, adding that "problems of unbalanced and insufficient economic development was acute". 

The readings follow a surge in factory price figures last week.  

The clean-air policy, which has been stepped up going into the winter when pollution worsens, has led to tighter supplies and in in turn lifting prices. 

NBS data showed growth in retail sales slowed to 10% in October, down 0.3 percentage points from September and also short forecasts of 10.5%.

Chinese fixed asset investment grew 7.3% from January to October, in line with expectations.

Analysts said a cooling property sector and slightly softer foreign demand weighed on the economy last month, while disruptions from the anti-pollution crackdown in the north-east of the country probably also contributed. 

This month's figures follow a string of positive indicators suggesting the economy is stabilising, with gross domestic product tipped to grow at a faster pace than the government's target this year. 

Trade data last week showed import and export numbers had softened slightly in October.