A diner in Dagupan City has closed temporarily after its portable butane stove exploded and injured several students during a birthday celebration, authorities said.

Investigators said the explosion happened shortly after 1 p.m. while the students were celebrating a classmate’s birthday. Authorities later found that gas overpressure caused the blast.

The Bureau of Fire Protection (BFP) said the use of a portable butane stove inside the restaurant violates the Fire Safety Code of the Philippines.

“Ang ina-allow lang talaga natin is ‘yung parang naka-system siya. Hindi natin ina-allow… ‘yung portable na butane indoor. Ang portable butane ay designed talaga for outdoor use lang,” FCINSP. Jun Eland Wanawan, fire marshal of the Dagupan City Fire Station, said.

The BFP said it is expected to issue a notice of violation to the restaurant management after the inspection.

Aside from the use of the portable stove, authorities also found that the establishment lacked enough fire extinguishers.

“They have to comply with our recommendation unless otherwise baka maipasara natin ‘yung establishment. Ang suggestion natin is pullout natin and then i-check muna isa-isa ‘yung mga cannister,” Wanawan said.

When GMA Regional TV One North Central Luzon returned to the diner, the establishment was temporarily closed while management conducts equipment maintenance and inventory.

The restaurant manager also declined to give a statement, according to a staff member.

Meanwhile, Dagupan City Police Station 2 said three of the eight victims who were admitted to the hospital have already been discharged.