Uefa has apologised to Liverpool and Real Madrid fans caught up in events around the Champions League final and said it must not happen again.
Liverpool fans described heavy-handed policing, organisational chaos and overcrowding at last Saturday's showpiece game.
Real Madrid have asked for answers on the "series of unfortunate events".
"No football fan should be put in that situation, and it must not happen again," said a Uefa statement.
"Uefa wishes to sincerely apologise to all spectators who had to experience or witness frightening and distressing events in the build-up to the Uefa Champions League final at the Stade de France on 28 May 2022 in Paris, on a night which should have been a celebration of European club football.