Chinese authorities released a plan on October 22 requiring the heavily polluted metropolises of Beijing and Tianjin as well as cities in Hebei Province to put more new-energy buses on the road to cut pollution.

China aims to promote the use of 20,222 new-energy cars in the region's public transport system from 2014 to 2015, according to the plan jointly released by seven departments, including the Ministry of Industry and Information Technology and the NDRC.

By the end of 2015, new-energy vehicles should take up no less than 16 percent of the total buses in those regions, the plan said. The total number of charging posts in areas targeted is projected to reach 19,657.

The announcement is the latest government effort to address increasingly serious pollution in the area.

Beijing and eight of its neighboring cities were among the 10 Chinese cities with the worst air quality in the third quarter.

The Beijing-Tianjin-Hebei region on average suffered from unacceptable levels of air pollution during 45 percent of the days in the third quarter, according to data released by the Ministry of Environmental Protection on October 21.