There are reports that Lazio supporters threw fireworks and explosive devices into the Napoli fans, one of which exploded in the hands of a child who has been taken to hospital.
The Biancocelesti emerged from the Stadio Diego Armando Maradona with a 1-0 victory thanks to a goal from Matias Vecino.
Throughout the match, loud explosions were audible from fireworks, paper bombs and smoke bombs thrown onto the pitch.
According to Canale 21, one of these fireworks was thrown from the away section into the Curva A where Napoli fans were situated.
A child picked it up, thinking it was just a smoke bomb, and it exploded in his hands.
The youngster has been taken to the San Paolo hospital and initial suggestions are that his life is not in danger, but his hands need further evaluation.
Lazio fans could also face punishment for ‘territorial discrimination’ chants against those from the south of Italy, that are treated in the same way as racist abuse.