A high school senior in Daegu tested positive for COVID-19 as the second step in the country's phased school reopening began on Wednesday.

The student was told not to attend Osung High School in the Suseong District from last Thursday when he exhibited coughing. After remaining in isolation through Sunday, the student returned on Monday but then was moved to a temporary observation room after coughing again.

The student tested positive for the coronavirus late Tuesday.

Quarantine authorities found that the student wore a mask at all times in school other than lunchtime and did not come into close contact with any other students or attend any private education institutes.  

However, concerns of related infections rose after authorities found that the student had come in contact with those from five other high schools. The Daegu education office temporarily halted attendance at the six schools, including Osung, and switched all classes to online.