West Ham and Fiorentina have been charged by Uefa in relation to incidents at Wednesday’s Europa Conference League final.
Both clubs have been charged with “throwing of objects” while the Hammers have also been punished for “invasion of the field of play”.
Fiorentina captain Cristiano Biraghi was struck on the head by something thrown from the West Ham end in the first half of the game in Prague.
The Hammers won the match 2-1.
Fiorentina have also been charged with “lighting of fireworks”. Uefa says the matter will be decided in due course.
Police said 23 fans were arrested in Prague. One was a West Ham fan, the rest supporting Fiorentina.
Fiorentina fans attacked West Ham fans in a bar in central Prague, with 17 of the 22 fans of the Italian club detained over that incident.