Remulla said the Philippine National Police (PNP) is conducting a thorough investigation to establish the motive behind the shooting, determine the ownership and source of the firearm used, and find out how it was brought inside the school campus.
The PNP is also looking into whether there were security or procedural lapses that may have contributed to the incident.
The DILG expressed its deepest condolences to the families of those who died and assured the school community that authorities are working to establish the circumstances surrounding the incident and ensure the safety and well-being of students and school personnel.
The department also urged the public to exercise restraint in sharing photos, videos and unverified information surrounding the incident, particularly content involving minors.
In a statement, PNP Chief P/Gen. Jose Melencio Nartatez Jr. said the police organization will provide verified information as appropriate and appealed to the public to refrain from sharing unconfirmed reports, photos or videos that may cause unnecessary concern.