Former São Paulo youth player Mikael Leandro, 15, died after being shot during a friendly football match in Maceió, the capital of Brazil’s Alagoas state.
The shooting occurred in the Pontal da Barra area.
He was taken to the State General Hospital after the attack and died while receiving treatment.
Civil Police said its preliminary investigation indicated that Mikael had been mistakenly targeted.
Investigators said they were examining whether the attack was connected to a dispute involving a drug-trafficking criminal group.
Police began questioning witnesses.
Authorities said several other people were shot, but did not disclose their identities or medical conditions.
Mikael, who was from Alagoas, had played for São Paulo’s age-group side earlier this year and won the Copa Fictor with the club.
After returning to Maceió, he had begun training with CSA’s under-15 team.
CSA expressed condolences to Mikael’s family and called for an investigation and for those responsible to be held accountable.
No arrests, suspected perpetrators, or further details on the motive had been disclosed.