At least 26 people have been infected with the new coronavirus in cases tied to a cram school in southwestern Seoul used for preparation for a state exam to pick public school teachers, the district office said Friday.

Two people who attended the private education institute in Noryangjin were confirmed to be infected with COVID-19 early this week and 24 more attendees and staff members contracted the virus, according to the office of Dongjak Ward.

Noryangjin is home to a slew of cram schools designed to help people prepare for state tests to become public servants and teachers.

The district office asked 214 people who came in close contact with the patients to be placed under self-quarantine for monitoring.

The outbreak of cluster infections came just one day before the country will conduct an examination to pick middle and high school teachers.

Health authorities warned the greater Seoul area, home to half of the country's 51.6 million, is in the third wave of the coronavirus outbreak.

The country added 363 more COVID-19 cases Friday, including 320 local infections, raising the total to 30,017. It marked the third straight day that daily virus cases hovered above 300. (Yonhap)