Bomb threats forced the suspension of classes at two Far Eastern University campuses and a Quezon City public high school this week, days after a school shooting in South Cotabato killed three people, The Philippine Star reported on September 25.

The scares add to a run of violence and threats at Philippine schools this year. In August, a junior high school student shot dead a classmate at Ateneo de Zamboanga before killing himself, while in June two high school students in Tacloban City killed three schoolmates in a shooting spree.

Classes and on-site operations at FEU's Alabang campus in Muntinlupa were halted at 11 a.m. after a bomb threat, with Muntinlupa police finding no explosives. A day earlier, the university's main campus on Morayta Street in Manila cut classes short after a similar threat posted on social media at around 7 p.m., which first reached the central student council and the medical technology society.

The Manila Police District's explosive ordnance disposal and canine unit swept the campus before normal operations resumed.

"All buildings, restrooms, and other campus areas were inspected manually and with bomb-detection canines. No explosive devices were found," the FEU Central Student Organisation reported.

The university said it is "closely working with law enforcement" to trace the origin of the threat.

At Don A. Roces High School in Quezon City, a threat posted on the school's Facebook page prompted officials to call in police. Operatives from the Kamuning police station and the district anti-bomb squad found no explosive or hazardous materials, but administrators suspended classes and administrative operations.

Police in Eastern Visayas tightened school security after a letter found on the campus of Biliran Province State University Laboratory High School in Naval town stated that several students were planning an attack.

"The safety of our learners is a shared responsibility. We heavily urge parents and guardians to closely monitor their children's activities, behavior and interactions, especially when they notice anything unusual or concerning," said Romano Cardino, Eastern Visayas police director according to the Star.

The Philippine National Police is weighing national adoption of an alert platform developed by Calabarzon police, already set for use in at least 155 schools.

"We are exploring the institutionalisation of this rapid response system to further help us identify and respond to threats in schools as well as ensure better coordination and swift action in any incident or challenge," PNP chief General Jose Melencio Nartatez Jr said in a statement.