China's environment authorities have stepped up efforts to ensure a blue sky and clean air for war commemoration activities centering on a military parade on Sept. 3.

The Ministry of Environment ordered Beijing and its six surrounding provincial regions to "swiftly take action" to ensure a sound environment during the events, its statement said on Friday.

Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Shandong and Henan authorities were given a deadline of Aug. 28 for monitoring various industries and shutting down companies with excessive emissions. Heads of the seven local governments will take the major responsibilities for the mission, it said.

Motor vehicles, especially trucks from out of town, will be restricted from entering the capital. Cars with excess emissions will not be allowed to enter.

In the ministry's latest inspections, it checked and regulated 241 companies, 45 construction sites and a large number of outdoor barbecue stalls. It also secretly visited some factories in Dingzhou City, Hebei Province, saying the environment situation there is "not optimistic."