Soccer fans of rival teams rioted before a Europa League quarterfinals match at the Parc Olyimique Lyonnais stadium in Lyon, France, on April 13 (video below).
The Lyon team was getting ready to play Besiktas, a team from Turkey, when the game was delayed because of the fans, reports France 24.
Fireworks and other projectiles were reportedly set off and thrown by the Turkish fans, and some fans ran out on the pitch for safety.
Lyon president Jean-Michel Aulas and other officials tried to calm the situation and convince the fans to go back to their seats. The match ended up starting 45 minutes late.
French authorities feared Turkish fans might attempt some kind of political demonstration in the run-up to a referendum in the country, and had designated the game to be "high-risk."
There was an attack against the Borussia Dortmund team bus on April 11, which resulted in an injured player and caused a game against Monaco to be delayed for 24 hours.
The French expected between 15,000 and 20,000 Turkish fans to come to Lyon for the game, and about 500 police officers were assigned to the stadium.
Fans were only allowed to enter the stadium with clothing, banners and flags that represented their country.
According to The Sun, some fans waving the Turkish flag and wearing black clothing -- the Besiktas team color -- clashed with police. Some fans also set off smoke bombs.
Some event workers were wounded, and had to be helped away by medical personnel and police. At least one fan was caught on video with blood running down his face.
Aulas told Lyon fans on April 10 to support the team "because there will be a strong opposition and many Turks inside the stadium," reports France 24.
However, the Lyon team ended up apologizing to fans for a "communication glitch" that resulted in Turkish fans buying up one-third of the seats for the game.
When the game finally started, Besiktas led 1-0 at halftime, thanks to a goal by Ryan Babel at the 15th minute mark, notes The Associated Press.
Lyon's player Corentin Tolisso scored at the 83rd minute, and Lyon scored again at the 84th minute after Besiktas goalie Fabricio "Fabri" Agosto Ramirezleft the goal open. Lyon won the match 2-1.
A return match is scheduled for April 20 in Istanbul, which reportedly has a reputation of being hostile to visiting fans.
The Union of European Football Association will fine both teams, but Besiktas will probably face heavier sanctions. The UEFA has the power to close sections of the Turkish stadium for the next game.