South Korea's military reported 19 additional COVID-19 cases, all of which are breakthrough ones, Monday, raising the total caseload among its personnel to 2,531.

Of the new cases, 13 people are from the Army, one from the Air Force, two from the Marine Corps and three from units under the direct control of the defense ministry, officials said.

Of the cumulative cases in the military, 279 patients are still under treatment.

Amid growing fears of the omicron variant, the military has toughened quarantine rules for troops returning from vacation and decided to start a booster shot program as early as Dec. 13 -- earlier than the initial plan to launch it at the end of this month. (Yonhap)