The military has confirmed its first COVID-19 infections linked to the omicron variant.

According to military sources on Wednesday, one officer in a unit in the central city of Daejeon directly under the defense ministry and two Air Force soldiers in Osan, Gyeonggi Province, tested positive for omicron.

All three cases were breakthrough infections, and reported only mild symptoms such as headaches. This is the first time that the variant has been detected within the military.

Military authorities suspect that the patients contracted the variant during an off-base trip or through contact with someone from the outside while on checkpoint duty.

Booster shots are expected to pick up speed, with the military planning to complete them on voluntary terms by January 14.