England and Russia have been threatened with expulsion from the European Championship if there is further violence by their fans. Expressing its "utter disgust" over three days of disorder in Marseille, UEFA told the English and Russian federations on Sunday "to appeal to their supporters to behave in a responsible and respectful manner" at the tournament in France, AP reported. The governing body said its executive committee "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 and the Russian Football Union, including the potential disqualification of their respective teams from the tournament, should such violence occur again." The English FA responded by saying it treats the UEFA warning with the "utmost seriousness." "We understand the potential implications of our supporters' actions and wholly accept that every effort needs to be made by the FA to positively urge them to act in a responsible and respectful way," the FA said.