BEIJING, Dec. 24 -- A huge amount of polluting production capacity was closed in 2015 as part of government efforts to combat persistent haze, an industrial watchdog said Thursday.

About 30 million tonnes of iron and steel production capacity were shut down this year, the Ministry of Industry and Information Technology (MIIT) said in an online statement.

Production capacity for electrolytic aluminum, cement and plate glass was reduced by 300,000 tonnes, 38 million tonnes and 11 million standard cartons, respectively.

Consolidation in the integrated circuit, rare earth and infant formula industries sped up in 2015, according to the statement.

"There was active progress in phasing out outdated and excess production capacity this year," said the MIIT.

Chinese cities, particularly those around Beijing, have been choked by smog this winter, with factory emissions blamed as one of the major pollutants.