A 16-year-old boy attacked a school in southern Brazil, killing a 9-year-old boy and injuring an 8-year-old girl and a 34-year-old teacher, authorities said on Tuesday.The attack took place at Maria Nascimento Giacomazzi School in Rio Grande do Sul, where the teacher was injured while trying to stop the assailant.Police confirmed the boy died from his injuries, while the girl and the teacher are in stable condition, as reported by AFP.Authorities have not confirmed the weapon used, but Estacao Mayor Geverson Zimmerman said the victims suffered stab wounds. He added that the suspect was known to the school staff and had been undergoing “psychological treatment.” Zimmerman also noted that security had been tightened at schools in the region due to a rise in similar attacks.Brazil has witnessed several violent incidents in schools in recent years. Earlier in April 2023, four children aged 4 to 7 were killed in an axe attack at a daycare centre in Blumenau, Santa Catarina. One of the deadliest school attacks in Brazil occurred in 2011, when a man opened fire at a kindergarten in Realengo, a suburb of Rio de Janeiro, killing 12 children before taking his own life.