China has pledged to cut PM2.5 concentration by at least 15 percent year-on-year in 28 northern cities from October to March to meet smog reduction targets, the top environmental authority said.

A new Beijing-Tianjin-Hebei regional environmental protection bureau will be set up and will begin a trial operation by the end of September to facilitate joint controls, it added.

The Ministry of Environmental Protection released a 143-page action plan on its website on Thursday night, listing detailed targets, controlling measures and punishments. The action plan covers Beijing, Tianjin and 26 other cities in the smog-plagued provinces of Hebei, Shandong, Henan and Shanxi.