An Indonesian teenager was sentenced to three years in a juvenile detention center for harboring a suspect in the Jakarta attack.

The 15-year-old boy, who cannot be identified because of his age, was captured last month along with Khumaedi, one of the main suspects in the Jan. 14 bombings in downtown Jakarta that killed eight people, including four attackers.

Judge Antonius Simbolon told the East Jakarta District Court the teenager was guilty of violating anti-terrorism laws.

The boy had pledged allegiance to the Islamic State group after watching extremist propaganda videos for weeks at his Islamic boarding school in West Java.

His parents were not aware of Khumaedi's identity or their son's radicalization.

The teenager is the first person with a link to the Jakarta attack to be sentenced.