Some 150 Russians were behind most of the violence around their country's Euro 2016 match against England in Marseille, a prosecutor said Monday.
Marseille prosecutor Brice Robin said the "highly trained" hooligans had come to the port city to cause trouble. He was quoted by AFP news agency as saying the group was prepared for "hyper-fast, hyper-violent operations."
No Russian fan was arrested in Saturday's clashes, in which 35 people were injured, Robin said.
Trouble broke out on each of the two days before the game, too, and Russian fans stormed a section with England fans after the final whistle of the 1-1 draw at the Stade Velodrome.
One person from England remained in critical but stable condition, Robin said.
Two British fans were sentenced to two and three months in prison respectively for their roles in the riots, AFP reported. The agency reported that each received a two-year ban on entering France.
Later, 10 fans from three countries appeared before a French judge, who sentenced at least eight of them to prison terms.
The harshest sentence was handed down to a 29-year-old Frenchman, who was received two years in prison, half of it suspended. He was convicted of kicking three people, as well as striking with his fist and belt.
Another Frenchman was sentenced to four months in prison, and a third received six months on probation.
Six Britons were sentenced to serve up to three months in jail for throwing beer bottles at police.
One Austrian was also convicted, but his punishment was not announced in the AFP report.
Most of the 10 defendants had no previous offenses and were drinking heavily prior to the violence.
The Interior Ministry said 116 detentions and three expulsions from France have taken place in football-related incidents.
Two Russian nationals were ordered to leave France, Robin said, but it wasn't immediately clear if they were among the three the ministry mentioned.
The ministry said additional bans on entry to France were issued for five people tagged as posing a "risk of trouble to public order."
European football body UEFA warned the teams Sunday that they could be disqualified from the tournament if the violence continued.
France is struggling to contain fan scuffles, as an extensive security networks has been deployed with the aim of deflecting a terrorist attack.
Partial alcohol bans were announced over the weekend by Interior Minister Bernard Cazeneuve, and local officials in Lyon said there would be no alcohol prior Monday nights Belgium v Italy.
Hooligan historian Sebastian Louis told French newspaper Le Monde that Russia supporters are trying to make a name for themselves in hooligan circles.
The chief of Britain's Euro 2016 police operations told The Guardian newspaper that the clashes Saturday were uncommonly violent, with Russia supporters coming highly prepared.
"England has had its problems with hooligans in the past. But the Russians are entirely different - they are like nothing we have seen before," assistant chief constable Mark Roberts said.
"They are highly organized and determined to carry out sustained violent attacks at a level of aggression I have not encountered in the past 10 years."
The Russian football fans involved in the fighting in France were essentially given a thumb's up from back home.
"I don't see anything terrible in the fans' fight. On the contrary, our guys did a good job. Keep it up!" Igor Lebedev, a member of the Russian Football Union's executive committee and a vice speaker of Russia's parliament, said on his Twitter page.
"What happened in Marseille and other cities in France is not the fault of the fans but the inability of the police to adequately organize such events," Lebedev continued in another tweet.
In an interview with the Life News agency published the day of the match, Lebedev, a member of Russia's ultranationalist LDPR political party, said that if Russian Sport Minister Vitaly Mutko were there, he would have fought alongside the fans.
"I personally believe that if Mutko were with the fans in the stands and were not an official figure, he would have also gone to fight the English fans, as the provocation came from that side," Lebedev was quoted as saying.