South Korea reported 2,86 new COVID-19 cases on Sunday, of which all but 28 were locally transmitted.
It's the second highest daily figure for a Sunday.
Infections remain concentrated in the greater Seoul area, which accounts for more than 74 percent of them.
A cluster infection has been reported at a military base in Yeoncheon, Gyeonggi-do Province.
Among the 46 people who tested positive, 41 were fully vaccinated and the other five had gotten their first shot.
Health officials think those infections may have been due to their communal living situation.
Authorities also remain on high alert over a possible uptick in cases following two extended holidays National Foundation Day this week, and Hangeul Day the week after.
"Concerns remain that infections traced to the Chuseok holiday could spread further and that the virus could also spread more following the two extended holidays."
He cautioned that the reproduction rate, meaning the number of people a single person is likely to infect, came to 1.2 last week, the highest since the third week of July.
With the daily case still high and expected to rise, the government has decided to extend the current social distancing measures for two more weeksuntil October 17.
Bans on private gatherings will remain in effect, but a few exceptions have been made for special occasions.
Notably, weddings will be allowed to have up to 99 people if at least 50 of them are fully vaccinated.
But for weddings where no food is served, the limit goes up to 199 if at least a hundred people are vaccinated.
Restrictions have also been eased for parties celebrating baby's first birthday, a major Korean tradition, with up to 49 people allowed if guests beyond the basic limit are all fully vaccinated.
The country is also planning to get teenagers vaccinated in the remaining three months of the year.
From Monday, 16- and 17-year-olds can make appointments and get their shots starting mid-October, while those aged 12 to 15 will be vaccinated from November.
Appointments for booster shots will also be available this week to people 60 and older who've been fully vaccinated for six months.
So far, almost 40 million people have received at least one dose of a vaccine, and about 26 million have been fully vaccinated, which is more than 50 percent of the total population.
Min Suk-hyen, Arirang News.