The Ministry of National Defense disciplined a military official for taking part in a deployment to set up a martial law command in the early hours of Dec. 4, its first such disciplinary action in connection with former President Yoon Suk Yeol's declaration.

According to the ministry on Wednesday, the Army's disciplinary committee handed down a probation sentence, the second-lowest disciplinary measure, to Brig. Gen. Kim Sang-hwan, head of the Army's legal office.

Kim, who is scheduled to leave the military on Sunday, had applied for an honorable discharge.

Kim and 33 other officers boarded a bus bound for the ministry's headquarters in Seoul in the early hours of December 4 on the orders of then-martial law Commander Park An-su, even though parliament had already passed a motion revoking the decree.

The bus returned to the Army's headquarters in Gyeryong 30 minutes after departure.

The ministry is reportedly close to completing its investigation into those who boarded the bus through its own audit. Administration policy requires that each ministry and agency form a task force to investigate officials' illegal acts related to the decree.