Authorities in Tianjin municipality pledged to accelerate efforts to reduce pollutants emitted by vehicles, a major cause of the smog that has frequently hit the city, within the next few years.

Measures include gradually phasing out so-called yellow-label cars and improving the quality of automotive fuel, according to the city's latest fresh air plan.

Yellow-label cars are heavy-polluting vehicles that do not meet phase I emission standards.

A total of 290,000 such heavy-polluting vehicles will be removed from the roads in the city by 2015, Li Qiang, a local official on environmental protection was quoted as saying by Xinhua News Agency.

By the end of 2012, the city had phased out 57,000 such vehicles. Heavy-polluting vehicle owners have been given subsidies of 18,000 yuan ($2,960) for phasing out each vehicle, the report said.

All yellow-label cars will be banned from urban areas in the city as well as built-up areas within the jurisdiction of Tianjin by the end of 2014, according to the plan.

Meanwhile, the city will build up a supply of motor gasoline that meets the national fourth-phase standard by the end of next year and an overall supply of motor gasoline that meets the national fifth-phase standard will be realized by the end of 2015, it said.

At present, the number of motor vehicles in Tianjin is about 2.4 million, emitting 500,000 metric tons of pollutants annually, the report said.