Padang, West Sumatra. Indonesian counterterrorism police have arrested a 17-year-old student after a homemade explosive device detonated inside a classroom at a state Islamic high school in Padang, West Sumatra, on Tuesday. No one was injured in the incident, authorities said.

The teenager, a student at the state Islamic high school MAN 3 Padang, is the only suspect identified so far.

According to the preliminary investigation, the suspect told investigators he had been inspired by an explosion at a Jakarta high school last year.

Police's counter-terrorism squad Detachment 88 said the teenager also admitted to learning how to make explosive materials through online sources.

“The suspect also admitted joining several online groups that discuss the manufacture of explosive materials. Those statements are still being verified and remain under further investigation,” Detachment 88 spokesperson Mayndra Eka Wardhana said.

The case came to light after school security personnel discovered a suspicious object believed to be a homemade explosive on the school grounds and alerted police.

Investigators recovered a number of items they believe are connected to the case, including a black box, a backpack, a mobile phone, firecrackers, a knife, arrows, marbles, bolts, and other materials.

Police said the items are believed to belong to the teenage suspect, who was taken into custody for questioning.

Detachment 88 is continuing to investigate the suspect's online activities, the source of his inspiration, and the identity of the intended target, if any.

Mayndra said the explosion caused no fatalities or injuries. All evidence has been secured as the investigation continues.

The blast triggered panic among students and teachers, prompting an evacuation of the school. Bomb disposal officers later searched and secured the scene to ensure no additional hazardous devices remained.

The investigation follows a similar incident at a Jakarta high school on Nov. 7, 2025, when a homemade explosive detonated on campus. Police subsequently arrested a student and said investigators had uncovered digital evidence suggesting the suspect had accessed violent online forums and purchased materials used to make explosives.

Authorities in that case also said investigators found indications that the suspect had visited online forums featuring violent content and had followed online communities discussing real-life crimes. Police recovered a replica rifle bearing the names of convicted mass killers during the investigation. The explosion injured 96 people, several of them seriously.