British politicians and fans on Sunday condemned the treatment of fans around the stadium before Saturday's Champions League final, when French police sprayed tear gas on Liverpool supporters.
Northern Ireland Secretary Brandon Lewis told Sky News on Sunday: "It is concerning to see that people either didn't get into the stadium or were ... treated with a very aggressive approach."
Earlier the politician who oversees the sector, the Secretary for Digital, Culture, Media and Sport Nadine Dorries, tweeted of "troubling reports" from the stadium.
A Liverpool MP from the opposition Labour Party, Ian Byrne, tweeted that "I've just endured one of the worst experiences in my life. Horrendous security and organisation putting lives at risk".
Merseyside Police said in a statement that there were "distressing scenes at the match," where its officers were deployed.
The force insisted "the vast majority of fans behaved in an exemplary manner".
Liverpool players were set to take part in an open-top bus parade through the city on Sunday afternoon despite losing in Paris. Police said the city would be "very busy".
Liverpool Mayor Joanne Anderson tweeted: "I know many have had a distressing time," adding that she supported the club's "call for an explanation into what happened before kick off."
Liverpool supporters' association Spirit of Shankly wrote on Twitter that "Last night was totally shambolic & extremely dangerous - we are gathering evidence from fans & @FansEurope and will be making a statement later."
One fan, Paul Machin said in a YouTube video that what he witnessed in Paris was "unlike anything I've seen at a football match before", condemning "totally and utterly reprehensible behaviour from the French police who were an absolute disgrace".
Another fan, Andrew Whittle, told Sky News that "Everyone was just funnelled into one place" and the crush "was a real Hillsborough sort of moment", referring to the 1989 stadium disaster at a Liverpool match.
Former Liverpool defender Jim Beglin tweeted that after the match "organised gangs set about mugging departing fans" with "not a police officer in sight".
Another former Liverpool star Kenny Dalglish said on Twitter that "the way they (fans) were treated by authorities was an absolute joke. Nobody should ever be afraid to go to a football game."
European football governing body UEFA blamed "fake tickets which did not work in the turnstiles" for a 35-minute delay to the final between Liverpool and Real Madrid.
UEFA said French police had fired tear gas to disperse thousands of frustrated fans who were building up outside the Stade de France as a result of the fake tickets issue.
But Liverpool said they were "hugely disappointed" that their supporters had been subjected to an "unacceptable" breakdown of the security perimeter at France's national stadium.
UEFA said they were "sympathetic" to the fans affected and would review the situation together with local police and authorities, as well as the French Football Federation.
However, French Interior Minister Gerald Darmanin pointed the finger at the Liverpool fans, tweeting that "Thousands of British 'supporters' either without tickets or with fake ones forced their way through and sometimes behaved violently towards the stewards".
