Beijing on Friday introduced stricter vehicle emissions regulations, which the environmental authority expects will reduce auto pollution by 40 percent.

The fifth phrase of emissions standards for automobiles, designed to reduce emissions of nitrogen oxide, carbon monoxide and hydrocarbons, will improve air quality in the capital, the Beijing Environmental Protection Bureau said.

Light vehicles running on gasoline that fail the strictest emissions standard will be barred from sale or registration in the city, said Li Kunsheng, director of the bureau's department of motor vehicles.

The bureau will carry out a random examination of vehicles to ensure implementation.