England and Russia could be thrown out of Euro 2016 if violence involving their fans continues through the tournament, UEFA has confirmed.
Saturday's 1-1 draw between the two sides was marred by heavy violence before and after the game, with both sets of fans clashing in Marseille.
At the end of the game, Russian fans forced their way through security barriers in the Stade Veldrome's south stand and proceed to attack England supporters.
UEFA confirmed on Sunday that it will open disciplinary proceedings against the Russian Football Union as a result and expressed its "utter disgust" at the violent scenes.
And both sides have been warned that they could be disqualified from the tournament if there is a repeat of such violence.
"Such unacceptable behaviour by so-called supporters of the national teams of England and Russia has no place in football, a sport we must protect and defend," a statement read.
"The UEFA Executive Committee has warned both football associations that – irrespective of any decisions taken by the independent disciplinary bodies relating to incidents inside the stadium – it will not hesitate to impose additional sanctions on the Football Association (FA) and the Russian Football Union (RFS), including the potential disqualification of their respective teams from the tournament, should such violence occur again.
"We urge both the FA and the RFS to appeal to their supporters to behave in a responsible and respectful manner.
"We would also like to publicly voice our support for the work of the French authorities and security forces for their efforts to deliver a safe and secure tournament in challenging circumstances."