Police chief Maurilio Ochoa told the media that six people had been wounded – five schoolchildren and a teacher – with two in a “delicate” condition in hospital.

Ochoa said the shooter was believed to have entered his school with two weapons: a small-calibre handgun and a high-calibre weapon. The boy’s parents and grandmother, with whom he lived, had said they had no idea how he acquired the guns.

“This is really regrettable,” Ochoa said, as anxious parents gathered outside the school’s entrance. He suggested backpack searches might be needed to prevent future tragedies.