European football's governing body UEFA has announced that they will launch an investigation into the shocking scenes of crowd trouble during Roma's Champions League match against Manchester United in the Italian capital tonight.
Baton-wielding riot police laid into the visiting fans inside the Stadio Olimpico after trouble broke out during the match.
UEFA communications director William Gaillard, who was actually in the stadium, said: "I only saw glimpses of what went on, I saw some missiles flying and the police charging.
"We will be waiting for the delegate's report and the control and disciplinary body will be looking at the television images to see the dynamics of what actually happened."
Roma could face action if they are judged to have failed in their security arrangements. But if Manchester United fans are found to have a played a significant role in provoking the police's reaction, they could be in trouble - especially as only last month they were fined for the misbehaviour of some supporters in Lens during the Lille game.
Gaillard said the police's response would be studied by UEFA. He added: "In Italy, the police are in charge of security in the stadium, stewards have nothing to do with it.
"We will also have to see what role Manchester United fans had in the incidents because they had some problems in Lens earlier this year."
UEFA are not expected to make a decision on disciplinary action until after the Easter weekend.
Trouble flared after Roma scored the opening goal as rival fans surged towards a barrier separating them and missiles were thrown.
The 'Carabinieri', situated only in the visiting supporters' area, responded with some savagery and officers were seen repeatedly striking the Manchester United supporters, including at least two as they lay on the floor.