A 25-year-old attacker invaded a preschool in southern Brazil and killed four children Wednesday with an axe-like weapon before turning himself into police, authorities said.

“It is with immense sadness that I received the terrible news that the Good Shepherd preschool in Blumenau was invaded by a murderer who attacked children and employees.

“Unfortunately, four were killed,” Santa Catarina state Governor Jorginho Mello said in a statement, declaring three days of mourning.

President Luiz Inacio Lula da Silva condemned the attack as a “monstrosity.”

“There is no greater pain than a family that loses children or grandchildren, even more so when it is in an act of violence against innocent and defenseless children,” he wrote on Twitter.

“My thoughts and prayers are with the victims’ families.”

A state government source confirmed to AFP the four victims were children. Brazilian media reports said the weapon used resembled a hatchet.