RIO DE JANEIRO — A 16-year-old attacked children in a school in Brazil’s southern state of Rio Grande do Sul on Tuesday, killing a 9-year-old, authorities said. The attacker was arrested shortly after.

Another child and a teacher were also injured in the attack in the Estacao municipality, police said in a statement. The teen used a knife, according to local news outlet G1.

The motive was not immediately clear and an investigation was underway, police said. The teen had no criminal record and police did not release his identity or other details.

Estacao’s town hall said that following the attack, classes had been suspended across the area for an undetermined period.

“What happened cannot be normalized, downplayed, or forgotten,” Gov. Eduardo Leite said on X, adding that he would strengthen strategies for protection and care in schools.

School attacks in Brazil have happened with greater frequency in recent years.

In 2023, four children were killed after a man with a hatchet burst into a day care center in the neighboring state of Santa Catarina.