A man with a hatchet burst into a day care center Wednesday in Brazil, killing four children, authorities said, in an attack that shook the country and put pressure on the government to curb a rising tide of violence.

At least four other children were wounded in the attack in Blumenau, a city of 366,000 in southern Brazil, near the Atlantic coast.

The assailant, who got inside by jumping over a wall, turned himself in at a police station, officials said. He did not appear to have any connection with the center, which offers nursery services, preschool education and after-school activities. The dead were between the ages of 5 and 7, authorities said.

Authorities were searching for a motive, the police detective leading the investigation, Ronnie Esteves, told television reporters.

Hours after the attack, the justice and education ministers pledged to invest in new violence-prevention efforts.

Valeria Aparecida Camilo, the mother of 5-year-old girl at the center, said she was working when a colleague saw the news. She called her husband, Gustavo, who rushed to the school and later learned that his daughter had survived.

Franciele Chequeto said one of the girls killed was friends with her 7-year-old son, Gabriel.

The state’s civil police chief, Ulisses Gabriel, confirmed that the attacker was a 25-year-old man from neighboring Parana state. He will be charged with murder and attempted murder. Police believe the attack was an isolated act and not related to any other crimes, Gabriel said.

Images broadcast on networks showed weeping parents outside the private day care center called Cantinho do Bom Pastor.

The attack took place on the center’s playground, according to the local affiliate of television network Globo. NSC, the affiliate, showed a photo of the suspect with a closely shaved head. Police have yet to confirm his identity.

Blumenau’s mayor, Mário Hildebrandt, suspended classes and said he will declare a 30-day mourning period. Authorities said any reports of other attacks or threats against schools in the region were false.

School attacks in Brazil have happened with greater frequency in recent years. Last week, a student in Sao Paulo fatally stabbed a teacher and wounded several others in Sao Paulo.

Brazil has seen at least one past attack on a day care center. That attack also occurred in Santa Catarina state, in May 2021, when an assailant used a dagger to kill three children under 2 years old and two adults.

From 2000 to 2022, 16 attacks or violent episodes happened in schools, four of them in the second half of last year, according to a report from researchers led by Daniel Cara, an education professor at the University of Sao Paulo. The 12 researchers — comprised of psychologists, social scientists, public school educators, journalists and activists — prepared the report for the government of President Luiz Inácio Lula da Silva.