An explosion near a school in Indonesia’s capital Jakarta left 54 people injured on Friday, police confirmed, as investigators worked to determine the cause of the blast.

Jakarta Police Chief Asep Edi Suheri told reporters that the explosion occurred “in the vicinity” of a local high school in the densely populated city. “The initial data we have received indicates that there are approximately 54 individuals affected,” he said during a press briefing broadcast by Kompas TV.

“Some have minor injuries, some moderate, and some have already been discharged,” Asep added, noting that several victims were treated on-site while others were taken to nearby hospitals for further care.

Authorities quickly cordoned off the area, deploying bomb disposal units and forensic teams from Jakarta Police to examine the scene. Officers were seen combing through debris and collecting evidence as part of the ongoing investigation.

“We are still investigating, as this incident just occurred,” Asep stated, stressing that the cause of the explosion had not yet been identified.

In addition to securing the blast site, police established information centres at two hospitals to help relatives locate injured victims.

Emergency services remained on high alert throughout the afternoon as investigators sought to establish whether the explosion was accidental or deliberate.

Local residents reported hearing a loud bang followed by scenes of chaos as bystanders rushed to help victims near the school. No fatalities have been reported so far.

Authorities said further details would be released once the investigation and forensic analysis were complete.