Police have launched an investigation after a middle school kendo coach allegedly assaulted a student with a bamboo sword.

The Uijeongbu Police Station in Gyeonggi Province announced that it has booked and is investigating A, a contract coach who trains kendo athletes at a middle school, on charges of violating the Child Welfare Act.

Coach A is accused of striking student B, a member of the kendo team, with a bamboo sword for more than 30 minutes during a training session.

At the time, student B was wearing protective gear, but reportedly suffered severe injuries, including bruising and swelling around the eyes and face.

A hospital that treated student B diagnosed that continued outpatient treatment is necessary to screen for "delayed complications of ocular trauma," which are aftereffects that can appear some time after an eye injury.

Upon learning of the incident, the school reported Coach A to the police on child abuse charges.

The school stated, "We understand that Coach A struck the student with a bamboo sword while wearing protective gear out of excessive zeal, intending to make him focus because the victimized student was unable to properly perform training motions and failed to follow instructions despite multiple warnings."

Coach A has reportedly admitted to the police about striking student B with the bamboo sword.

Police stated, "The victimized student's side requested a postponement of the interrogation schedule due to ongoing medical treatment, so we have not yet conducted the victim investigation." They plan to summon Coach A and student B sequentially for questioning in the near future.

The school stated, "The school principal has currently requested a disciplinary committee to take action against Coach A, and he has been separated from the students."

(Reported by Kim Taewon | Video by Ahn Jun-hyeok | Graphics by Lee Jung-joo | Produced by SBS Digital News)