A group of university students are being taken to the Seoul Western District Court in the capital to attend a hearing to review the legality of their detention over their attempt to break into the presidential office. (Yonhap)

The defense ministry's investigation unit has begun a probe into student activists who attempted to enter the presidential office this month over their possible violation of military law, officials said Thursday.

The ministry's Criminal Investigative Command has booked some 10 members of the Korean University Progressive Union on charges of injuring sentry guards and trespassing at a guard post during their attempt to enter the presidential office in central Seoul on Jan. 6.

The presidential compound shares its entrance with the defense ministry as the current administration relocated the presidential office to its current site when it launched in May 2022.

The ministry said it is looking into whether the incident violated military law, separately from the prosecution's case.

Prosecutors had sought arrest warrants for 10 members of the activist group over the attempt but a Seoul court rejected them on Jan. 9.

Before the attempt, the activists had staged a protest outside the compound, demanding a special probe into first lady Kim Keon Hee and a meeting with presidential officials.