Three students have been killed and more injured after two of their peers opened fire at a high school in central Philippines, police say.

Investigators believe the suspects, aged 14 and 15, were motivated by a "grudge" over bullying. One was arrested soon after the shooting at the San Jose National High School in Tacloban city while the second later surrendered.

The suspects were armed with a .38 revolver and a 9mm pistol, the latter of which belongs to a policewoman who is one of the suspect's relatives and is now in custody.

Gun violence is not uncommon in the Philippines, but school shootings are extremely rare.

"Red flags" in the teens' behaviour had been missed and with them the opportunity to prevent the crime, the national police spokesperson told reporters on Monday.

"The two [suspects] went straight to the classroom. Without saying anything, they started firing," Colonel Allen Rae Co told reporters.

"Initially, it appears that the motive of the crime is grudge for school bullying."

He said it was unclear at this stage of the investigation whether the intended targets were in that classroom.

About 40 empty shells have been recovered from the crime scene, Co said. Along with the three people who died, three were injured by gunshots, and four were wounded in their "panic" to get away, he added.

Investigators have found violent videos of one of the teens firing a gun on his social media, Co alleged.

"So this is very obviously red flags... we're not putting blame on anybody, but if anybody was able to monitor these red flags, this could have been prevented."

The mother of a slain 15-year-old student told Agence France-Presse whoever had allowed the shooters access to guns must be held accountable.

"I'm asking that the gun owners be charged, because the guns wouldn't have ended up in the children's hands if it weren't for them," Jennelyn Badoria said in an interview outside the school.

This is the first school shooting in Tacloban City in recent memory, Evalyn Diaz from the city police told BBC News.

"We call on parents who have firearms to be more responsible, hide their firearms, make sure those are properly hidden, talk to their children," Diaz said.

President Ferdinand Marcos's spokeswoman on Monday said the president had been "saddened by what happened".

"Anyone, especially the parents of the victims, would feel grief and fear," Claire Castro told reporters.

The education ministry has expressed "deep concern" over the incident. "We call on everyone to join us in praying for the safety, healing and recovery of those affected by this incident," it said in a statement.

Together with police, it announced a review of school security protocols, bullying policies, and student behavioural monitoring systems.

Police data show gun violence has been steadily declining in recent years. In 2024, the Philippine National Police recorded close to 5,000 gun violence cases nationwide.

Tacloban city, about an hour by plane from Manila, is home to 250,000 people.

Located on Leyte Island in the Visayas region, the city was among the worst-hit by Super Typhoon Haiyan in 2013 that killed 6,000 and plunged many in the region into deeper poverty.