South Korea reopened schools on Wednesday after a months-long closure, but high schools in five districts in the port city of Incheon sent students back home after some students were diagnosed with COVID-19.

The Incheon Metropolitan City Office of Education said seniors at 66 high schools in five of ten districts in the city were had to return home due to safety concerns.

High schools in the other five districts will stick to the reopening plan, but the education office may consider making changes after consulting with quarantine authorities. 

A spokesperson for the education office said they decided to send students from the affected schools back home as there is a high chance they visited the same facilities as the students who tested positive as well as to stem further spread of infections.