South Korea has begun enforcing measures related to auto emissions in a bid to reduce fine dust levels during the high-density winter season.

The environment ministry announced that it was implementing its seasonal management system from Thursday to March 31, marking the fourth time the system has gone into effect since it was introduced in 2019.

Vehicles designated as Grade Five for lacking low-emissions functionalities will be banned from 6 a.m. to 9 p.m. on non-holiday weekdays in Seoul, Gyeonggi Province and Incheon as well as Busan and Daegu. Violators will face a fine of 100-thousand won.

The ministry plans to further tighten regulations for such vehicles in Seoul, including charging extra for public parking.

Also through March 31, the government will be restricting operations of Grade Five emissions vehicles in Gwangju, Daejeon, Ulsan and Sejong on a trial basis. Drivers in these areas will receive information on the restrictions, but won't be subject to a fine. 

According to the ministry, the number of Grade Five vehicles fell from some two-point-one million at the end of 2019 to around one-point-one million at the end of October of this year.

The ministry is aiming to get rid of all Grade Five emissions vehicles by 2024.