European governing body UEFA said on Saturday it had opened disciplinary proceedings against the soccer federations of Croatia and Turkey for crowd trouble during the Euro 2016 tournament in France.
Both federations could face sanctions over fans "throwing objects and setting off fireworks", a statement read.
Croatia face additional charges over alleged "racist behaviour", while Turkey are looking at charges over supporters invading the pitch.
The incidents occurred on Friday during the Spain vs Turkey and Czech Republic vs Croatia matches. The hearing will take place on Monday.
The Croatia game in St Etienne was held up for several minutes after their fans threw flares onto the field and began fighting among themselves.
Eight flares and other objects landed on the pitch close to riot police, who had been deployed in front of the section housing Croatian fans.
The trouble broke out in the dying minutes of a game that Croatia were leading 2-1. The final score was 2-2.
Croatia, sanctioned three times during the qualifying competition, were already facing a disciplinary hearing on Tuesday after fans threw flares and ran onto the pitch during the team's opening match at the championships against Turkey in Paris.