The Philippine National Police (PNP) on Tuesday urged parents, teachers and school administrators to closely monitor minors' social media activity and gadget use following the deadly shooting at a school in Tacloban City involving two minors.

PNP chief Gen. Jose Melencio Nartatez Jr. said stronger parental supervision and school intervention are needed to identify early warning signs of violent behavior among children.

The call follows the 22 June shooting at San Jose National High School in Tacloban City that left three students dead and at least 13 others injured.

The PNP said the directive is aligned with President Ferdinand Marcos Jr.'s order, through Interior Secretary Jonvic Remulla, to strengthen community-based prevention measures and improve early detection of youth-related violence.

"Parents and guardians serve as the first line of defense. They must be present and vigilant in their children's digital lives, treating their online activity with the same level of concern as their physical whereabouts," Nartatez said.

He also called on teachers and school administrators to help identify behavioral changes among students that could signal potential threats.

"We are also calling on our teachers and school administrators to act as our partners in this digital watch, identifying early behavioral shifts or concerning interests in students so we can intervene long before any harm is done," he added.

According to police investigators, one of the suspects allegedly posted gun-related and violent videos online before the attack, including footage showing himself firing a firearm.

Authorities are examining the posts as possible warning signs that may have gone unnoticed or unreported before the incident.

Police are also investigating possible bullying and other social factors that may have contributed to the shooting.

"The warning signs are often subtle — social withdrawal, obsession with violent imagery, or the use of radicalized language — and when these red flags appear, early reporting to local police or school authorities is not just a precaution but a necessity to save lives," Nartatez said.

The PNP chief said the police force is coordinating with the Department of Education to formalize school safety protocols and strengthen preventive measures nationwide.

"We are currently working with the Department of Education to formalize these safety protocols because securing our schools is a shared, non-negotiable responsibility that requires the constant, active involvement of every adult in a child's circle of trust," he said.

The investigation into the Tacloban shooting remains ongoing.