UEFA has launched an investigation after three days of mayhem in Marseille ended with violence inside the Stade Velodrome when Russian supporters attacked English fans at the conclusion of a 1-1 draw played in the shadow of appalling violence across the city.
Shocking scenes of violence both in the city and inside the stadium could have consequences for both nations and the competition, with UEFA disciplinary action likely to be followed by tough questions over the security surrounding the game.
There are likely to be calls for a review of security arrangements ahead of England's game against Wales in Lens on Thursday, which is preceded on Wednesday with Russia playing Slovakia in nearby Lille.
For a third day running, rival supporters and the security forces were involved in violent clashes that saw more than 20 England fans treated in hospital, and one left in a critical condition.
Local media quoting Marseille police say a total of 35 people were injured in Saturday's violence, four seriously, but their nationalities are yet to be confirmed.
After violence rumbled into the early hours of Saturday morning, it resumed in mid-afternoon in the Vieux Port as police struggled to contain tens of thousands of fans, and resorted to tear gas and water cannon to try and maintain order.
A group of Russian supporters, active late on Friday, appeared to be provocateurs, launching attacks on England supporters, many of whom had been drinking all day, and evading the police.
In one episode a man was kicked repeatedly in the head and apparently required resuscitation.
In another, a fan was struck on the head with a chair and crumpled to the ground.
The huge quantities of beer bottles discarded were used as missiles between rival fans, and were also aimed at police who once more struggled to stem the violence.
Violence flared outside the Stade Velodrome before the match too, with Russian and English supporters trading volleys of bottles an hour before kick-off. Police once more used tear gas and water cannon.
There was a brief respite during the game, which ended in a draw after Russia salvaged a late equalizer to ensure England's record of never having won a European Championship opening game continues.
Tottenham's Eric Dier put England ahead with a wonderful free kick in the 73rd minute, before Vasili Berezutski steered a header beyond Joe Hart in the second minute of added time.
Both teams now lie behind Wales in Group B, who beat Slovakia in their opening game, but there will be equal concern at the consequences of the appalling scenes in Marseille.
For all the provocation and complaints about police tactics, England fans were not blameless in the most violent scenes at a major championship since Euro 2000.
That tournament that left England at risk of being ejected from European competition and the Football Association will await UEFA's ruling with some anxiety, as should the Russian FA.
Russian supporters were involved in violence at Euro 2012, and the country is hosting the next World Cup in 2018.
Russia's sports minister, Vitaly Mutko, has said the country's football union will probably be fined by UEFA for Russian fans' behavior before the match, the R-Sport news agency reported.
French interior minister Bernard Cazeneuve condemned the violence, praised the security services and said anyone arrested would be banned from stadiums and fan zones.
"The security forces can't be diverted from their public security mission by the reckless behavior and deliberate pseudo-fans whose only motivation is to disrupt public order and whose interior minister condemns the unacceptable conduct," he said.
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