(Volunteers use sewing machines to make masks to donate to the poor amid the coronavirus outbreak on March 18, 2020, in Seoul)[Getty/Kyodo]
South Korean health authorities on Sunday revealed that among people in the country who recovered from the novel coronavirus, 111 subsequently tested positive again.
The Korea Centers for Disease Control and Prevention said an investigation is underway to determine whether the virus had been "reactivated" in such people, or if they had been reinfected by other people.
The findings will be shared with the Geneva-based World Health Organization and used for treatment, it said.
Cases of some COVID-19 patients testing positive again after returning a negative result have also been reported in other countries.
Also Sunday, the KCDC reported 32 more cases of COVID-19, raising the national tally to 10,512.
The nation's death toll from the virus, which emerged in China late last year, rose by three to 214.