Italian media outlets are reporting that a group of Spaniards, an American and a British person were stabbed in violence linked to SS Lazio's upcoming European match against Sevilla.
The Biancocelesti host Sevilla on Thursday in the first round of knockout matches in the Europa League, having edged through the group stages just ahead of Apollon Limassol, but some nine points behind Group H winners Eintracht Frankfurt.
There have been concerns ahead of the game surround safety precautions due to the reputation of football-related violence in Italy, and Gazetta dello Sport reports that an attack has taken place some 24 hours before a ball has even been kicked in Rome.
Ultra groups from Sevilla and Lazio's fanbase supposedly met each other at a pub near the Colosseum, somewhere that Gazetta adds is a regular place for opposition fans to meet with the Biancocelesti Ultras.
Journalist Michele Galvani said on social media in the aftermath of the clash that the area looked like a war scene.
It's claimed that a group of Spaniards - likely travelling supporters - an American who was just "passing through" and a British person were among the victims of knife crime in the Italian capital.
Two people are in a serious condition at the city's Santo Spirito hospital.
The Mirror adds that up to 40 people were involved in a brawl that happened at an Irish bar in Rome on Wednesday, while La Gazetta dello Sport claims that Rome is now preparing for "another day in a state of permanent alert" following the latest incident of fan violence.
Violence with supporter groups in Italy is a huge problem that the footballing authorities have struggled to clamp down on. Not only is the sheer volume of people involved in an incident like this a problem, but only a handful of clubs actually own their stadium which can make identifying troublemakers a serious issue.