Local police chief, Captain Campos said the authorities did not know what had caused the incident, but no one was injured.
The threats occurred at the Colégio da Imaculada Conceição, in Cernache,to the South of Coimbra.
“A police car was called to the Colégio da Imaculada Conceição school, at about 9am this morning, but the two teachers had already convinced the boy to hand over the weapon and ammunition”, he said on Tuesday.
The 32mm “Tauros” revolver was loaded.
The police took the youth to Coimbra Paediatric Hospital for an assessment.