SUZANO, Brazil (Reuters) - Stunned family members on Thursday prepared to bury the eight victims of a school shooting in Brazil, along with the two attackers who carried out the violence, and grappled to understand why the bloodshed took place.

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A collective wake for six of the victims was held in a large sports arena in this city on the eastern outskirts of metropolitan Sao Paulo. Lines of mourners snaked outside the building, while inside, grief-stricken family members hugged and cried over caskets holding the teenagers killed.

The attack has shocked Brazil, a country with the world’s highest number of murders but where school shootings are relatively rare. The rampage has raised tough questions about just how to deal with a wave of violence that helped pave the way for the election of far-right President Jair Bolsonaro.

A total of 10 people, including the two attackers, were killed on Wednesday, Sao Paulo police said. The students who died were boys, mostly between 15 and 16-years-old. The assailants were aged 17 and 25, and carried out the attack with one .38 caliber pistol, a crossbow, as well as with hatchets and knives.

Another 10 people, mostly school children, were shot or cut, and several are in serious condition, police said.

The two attackers committed suicide as police closed in on them inside the school, authorities said.

“This is all too sad. These things happen because of a lack of love, a lack of God,” said mourner Solange Cardoso, as she stood outside the arena. “Suzano is in mourning. I am here to stand with the families, just like many of the people who are out here today.”

Investigators told Reuters the attack was inspired by the 1999 Columbine massacre in the United States.

Before entering the Raul Brasil school in Suzano near Sao Paulo, the two former pupils shot and killed the younger assailant’s uncle, who owned a car rental agency where they stole a vehicle.

An amateur video aired by Globo TV showed children screaming, running and begging for their lives as loud shots were heard.

Children climbed and jumped over a wall that surrounds the school building, then sprinted down streets, screaming for help, security-camera footage from homes nearby showed.

The two assailants spent more than a year planning their attack, investigators said.

A motive was not yet clear. The school is in a middle-class neighborhood and has about 1,000 students aged 11 to 16. One teacher told police that the younger attacker had been bullied while he was a student there.

The last major school shooting was in 2011, when 12 children were shot dead by a former pupil in Rio de Janeiro.

Gun laws are strict in Brazil, but it is not difficult to illegally purchase a weapon. Bolsonaro made relaxing gun control a cornerstone of his campaign last year.