Three Tottenham fans were taken to hospital after an attack on a pub in Lyon filled with travelling supporters ahead of Thursday's Europa League tie.
Up to 150 fans were inside the Smoking Dog pub in Lyon on Wednesday night when the establishment was smashed by iron chairs, wooden objects and a flare, according to eyewitnesses.
Three fans were admitted to hospital as a result of the incident which comes just four months after an apparent anti-Semitic attack in Rome ahead of Tottenham's Europa League group stage clash with Lazio.
The pub's landlord, Dave Eales, insisted the attack was unprovoked and confirmed a head injury to one of the Spurs fans.
"At 10.18 the pub was rammed with Tottenham fans watching the Champions League on the television," Eales said. "The front of the pub, which is made up of reinforced glass, was attacked by 20-25 people.
"They threw projectiles through the windows. There was a stand-off. They didn't get in to the bar. Then it calmed down. Then they came back a second time and it all started again.
"There were three injured Tottenham fans taken away by ambulance. One of them had a head injury. I'm not sure how bad it was."
A witness, who wishes to remain anonymous, revealed there were two assaults which may have been racially motivated.
"There were 50 who attacked in the first wave and 25 in the second," the witness said. "It's a pretty scary thing when you're confronted by people doing Nazi salutes.
"A lit flare was thrown through the window as well as the heavy weight, the kind that's used on terraces to hold down umbrellas. It was terrifying. I've never seen anything like it. They threw iron stools through the windows as well."
Tottenham fan Christian Radnege admitted the November attack in Rome made the travelling contingent more apprehensive.
"They came in making Nazi salutes. It was frightening," he said, according to Press Association Sport. "Rome was fresh in everyone's minds. Everyone realised this was serious. They left and then we thought that was it, but five minutes later it started again.
"The intruders did not get into the bar because it was full of Spurs fans. There were drips of blood left in the bar. The owners barricaded the pub between the two waves of attacks."
Metro journalist Aiden Radnedge, who is in Lyon, told Sky Sports News: "Local people here are expats who have been living here for a while, or are local business owners and they say they don't feel that this was Lyon related.
"That the perpetrators were wearing black balaclavas suggests something slightly out of the ordinary and I think that local people felt this was very much influenced by what happened in Rome a couple of months ago. People who wanted to carry out some kind of symbolic attack, rather than anything relating to Lyon."
Tottenham confirmed the reports on Thursday morning in a short statement via the club's official Twitter feed.
"Club officials attended an incident last night in Lyon. A group of around 50 people confronted fans," the club said.
"The situation was dealt with & arrests were made within the hour. Three fans sustained minor injuries & received prompt medical assistance.
"Spurs Officials & Stewards will be in the City throughout the day, along with match-day French police ahead of kick-off."
The website of French newspaper L'Equipe reported that three men were arrested, each believed to be Lyon ultras.
A spokesman for the Foreign and Commonwealth Office said: "We are aware of reports of an attack on British nationals in France and are offering consular assistance."
Information from the Press Association was used in this report.