Everton fans were left with injuries after being attacked by a group of men in Lille on Wednesday night, the Barclays Premier League club has said.
A considerable number of Toffees supporters are in the French city ahead of their club's Europa League Group H encounter with Lille at the Stade Pierre Mauroy on Thursday.
A statement issued on Everton's official website on Thursday morning said: "The club has been made aware of an isolated incident in a bar in Lille on Wednesday evening in which a number of Evertonians were attacked by a group of around 50 local men.
"The club understands that two Everton fans suffered minor facial injuries and were taken to the local hospital and that this was the only incident in what was otherwise a good-natured evening in the city centre.
"The club are in continual contact with Merseyside police officers who are in Lille today and the city's police representatives.
"Supporters travelling to tonight's match are advised to utilise the travel information provided on the official website where updates on any safety matters will also be provided."
It is understood at least 5,500 Everton fans will be in attendance at the stadium on Thursday evening.
In their statement on the incident, Merseyside Police confirmed the fans taken to hospital had since been discharged.
They also emphasised their officers had already been in Lille, as is common practice, to "support the police operation" at the game, and were unable to comment on reports of metal chairs being used in the attack or French police using gas in their bid to deal with the trouble.
A doorman for the bar, who said the attack had been unprovoked and suggested the group instigating it consisted of up to 100 people, told the Liverpool Echo: "In the evening they (the Everton fans) watched the Liverpool (v Real Madrid) game and towards the end of that match it happened. It was bad.
"The Lille hooligans just appeared from the Place Louise de Bettignies across the road, from a side street, and just ran at the pub.
"There were some Everton fans outside smoking and they got caught cold.
"The hooligans picked up chairs we had stacked up outside and attacked them while others used them to smash windows and try to get inside.
"We had to try and stop the Everton supporters inside from getting out to help because it would have got far worse. I went out to try and drag them in.
"I saw one older English guy being punched by about three Lille hooligans. His face was bleeding badly. I am so sorry for what happened."
Regarding the French police who arrived at the scene, the doorman added: "Some of the Everton fans were trying to explain. They were saying 'there are children inside' but the police were swearing at them and wouldn't listen.
"I saw them spray one Everton fan for no reason. He was just trying to reason with them."
Everton subsequently sent out a message to their fans on Thursday afternoon amid reports of a further flare-up in the city centre involving police and the use of gas.
The message said: "We advise Everton fans in Lille to avoid the main square in the city centre."
Images appeared on Twitter of Everton supporters having congregated en masse at Lille's Grand Place square, and of the French police then arriving and gas having been set off, with the crowd dispersing.
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