South Korea on Wednesday reported 444 new coronavirus cases 426 of which were locally transmitted.
And a whopping 83 percent of the local transmissions were from the Seoul capital region.
Many of these cases came from a spike in infections in the city of Dongducheon in Gyeonggi-do province.
Just in the first two days of March, this area alone saw 105 new infections.
Contact tracing is on the way, but the process has been stalled by a language barrier as foreign workers made up most of those infected.
"Foreign workers often have difficulty understanding prevention guidelines due to language or other problems. Also, due to their relatively poor workplace or accommodation conditions, they're more vulnerable to infections.
Meanwhile, the temporary COVID-19 testing centers are finding otherwise hidden coronavirus patients.
Amid Wednesday's tally, 113 cases, or more than a quarter of the day's local infections,. were found through these testing centers.
And another COVID-19 case was found among the inmates at a Seoul detention facility.
Health authorities fear that this could potentially spark another outbreak at the densely populated facility.
Six more deaths were reported on Wednesday, bringing the country's death toll to 1,612.
Kim Yeon-seung, Arirang News