Emergency fine dust reduction measures have been expanded to nine cities and provinces on Wednesday as fine dust concentrations remained at alarmingly high levels. 

The Environment Ministry said advisories were issued for the Seoul metro region, Busan, Daegu, Sejong, South and North Chungcheong Province and western parts of Gangwon Province effective from 6 a.m. to 9 p.m.

The ministry said local authorities will enforce a series of fine dust reduction measures. Such measures were enforced in the capital region and North Chungcheong Province on Tuesday as well. 

Accordingly, grade five emissions vehicles, the most polluting vehicles according to the government's five-tier system, will be banned from operation. Daegu and North Chungcheong Province, however, are not subject to the measure as they have yet to establish a related regulation.  

Public sector vehicles and those operated by public sector workers will also be subject to an alternating driving ban.

Private and public facilities that emit air pollutants have to adjust operations, while construction sites are also required to reduce or adjust their operations and take steps to curb dust emissions.