With a significant rise in COVID-19 cases in the capital region, residents in the greater metro area will be required to keep their masks on both indoors and outdoors even if they have been vaccinated.
Those who received at least one COVID-19 shot were to be allowed to take off their masks while outdoors starting on July 1.
However, health authorities on Sunday made it mandatory for vaccinated people in Seoul and nearby areas including Incheon and Gyeonggi Province to wear masks in public areas.
The government also banned alcohol in crowded outdoor settings such as parks and riverside areas after 10 p.m. in the capital region.
These measures will be in effect until a recent surge of infections in the greater Seoul area subsides.
The government plans to operate a quarantine inspection team to check virus-prone cram schools, indoor sports facilities in the region and conduct tests on employees at bars, karaokes and schools in the area.