The build-up to Thursday evening's Europa League Group H match between Everton and Lille at the Stade Pierre Mauroy was marred by two incidents in the city centre.
The first was an attack on some Everton supporters by a group of at least 50 people at a bar on Wednesday night, and the second a flare-up in the main square around Thursday lunchtime which saw French police use gas against Toffees fans.
Press Association Sport understands two Everton supporters were arrested on Thursday.
The club released a statement on Friday afternoon which read: "Everton will continue to work closely with the French and Merseyside police, in conjunction with the club's own security team, to better understand the two isolated but serious incidents that occurred in Lille ahead of our Europa League fixture this week.
"All available reports suggest that the first incident, on the night before the game, was an unprovoked and planned attack by local youths.
"The second incident, early in the afternoon on matchday, in the city's main square, quickly escalated into unwelcome and unpleasant scenes.
"Events then, equally quickly, returned back to normal with well-mannered and good-natured celebrations that were evident throughout the club's stay in Lille.
"The club will now work with all authorities to find out what happened and why.
"In order to gather as much detail as possible on the incidents and on other issues encountered by fans, the club has provided an online feedback form."
Around 5,500 Toffees fans witnessed the game - which ended 0-0 - from the away section of the ground, but there was talk that as many as twice that amount of Evertonians in total had made the trip to Lille.
Source : PA
Source: PA