A 50-year-old England fan is in a critical condition with severe brain injuries after being attacked by Russia supporters armed with iron bars, following violence in Marseille on the opening weekend of Euro 2016.
French prosecutors have also confirmed that six England fans, including a 16-year-old, have been charged after the clashes.
But despite the behaviour of the Russian fans, who fought running battles in the streets and also charged at England fans in the Stade Velodrome after Saturday night's 1-1 draw, no Russians have been arrested over the violence.
Brice Robin, chief Marseille prosecutor, told reporters the British teenager was in custody and that he had personally spoken to tournament organisers UEFA to have his future tickets cancelled.
He said about 150 Russian hooligans had been involved in the trouble, describing them as "hyper violent" and "hyper rapid". But he said just two Russian fans had been arrested, both for a pitch invasion.
The prosecutor said he did not think the Russian hooligans were "professional" but they "were extreme".
There were 12,000 Russian fans in Marseille who travelled to the city by train, he said.
UEFA has warned England they face disqualification from the tournament if the widespread violence is repeated.
The governing body branded the behaviour of both England and Russia fans before and after the game "unacceptable" and said it would not hesitate to impose additional sanctions.
It also opened disciplinary proceedings against the Russian Football Union for alleged crowd disturbances, racist behaviour and the setting-off of fireworks by its fans during the game on Saturday night.
Meanwhile, a Northern Ireland football fan died after a fall in Nice following the team's 1-0 defeat by Poland.
Darren Rodgers, 25, from Ballymena, toppled 26ft (8m) over a barrier from a promenade on to a hard pebble beach in the south coast city at around 2am on Monday, police said.