Thirteen foreign students enrolled in a university in Seongnam, just south of Seoul, have been diagnosed with COVID-19, municipal officials said Saturday.

The first coronavirus case of a foreign student occurred at the unnamed university in the city's Sujeong district on Wednesday, and two more expat students who lived together with the first patient tested positive for the virus the following day, the officials said.

On Friday, eight other foreign students were confirmed to be infected with the coronavirus, followed by two more on Saturday, they noted.

"Some of the infected foreign students, while working part-time, took the coronavirus tests in compliance with the provincial authorities' administrative order, with the rest getting tested at the recommendation of the university," a municipal official said.

"The latest mass infections on campus appear to have occurred as they lived together in groups of two to four," the official said, adding a search was under way for those who have come into contact with the infected students recently.

According to university officials, most of the infected foreign students have so far attended online classes. (Yonhap)