A 23-year-old South Korean man is under investigation for allegedly seeking to join the Islamic State terrorist group, and preparing for a terrorist attack while he was serving in the army.

It marks the country’s first case of a “lone wolf” terrorist act being planning.

The man surnamed Park, 23, was found to have stolen an ignition device for explosives while being trained at an army engineer school after joining an infantry unit near Seoul in October 2017, broadcaster KBS reported.

He allegedly propagated and instigated IS terrorist activities by collecting videos and materials of the group’s acts and uploading them on the internet from 2016 until recently.

A video showing how to make live ammunition was found on Park’s mobile phone, and a machete, or a broad blade that looks similar to the weapon often used by terrorists, which he bought online was found at his home.

A joint team of investigators from the military and police also reportedly found that Park installed a secret app used by IS members and supporters on his mobile phone, and received an email from a person believed to be an IS member on how to join the terrorist group.

Police began the investigation upon receiving intelligence from the US Federal Bureau of Investigation last year, and informed the military after confirming that Park was on active duty.

The Ministry of Defense said that the investigators sent Park to the ministry’s prosecutors office on July 1 for indictment on charges of stealing military equipment and violating the counterterrorism law.

As Park was discharged from military service on July 2, however, military prosecutors will look into his alleged theft of military equipment, while civilian prosecutors investigate his alleged counterterrorism law violations.

If convicted, Park will be the first Korean to be punished in Korea for planning terrorist acts in liaison with an international terrorist organization since the counterterrorism law went into effect in March 2016.

The IS claimed responsibility for a series of suicide attacks against churches and hotels in Sri Lanka in April that killed more than 320 people, just a month after the US said it has defeated the international terrorist group.

By Kim So-hyun (sophie@heraldcorp.com)