Liverpool are to "establish the facts" following reports of "heavy-handed" treatment at the hands of police and stewards in Tuesday's Champions League clash at Sevilla.
Supporters group Spirit of Shankly claimed that some travelling fans were refused entry into the Ramon Sanchez Pizjuan Stadium, while others were assaulted by police.
A statement released by the group's chairman Jay McKenna to ESPN read: "We became aware of issues affecting supporters during the first half of the match.
"A couple of our committee members reported problems getting into the ground, being refused access as the flag they had [which featured a Liver bird and the word "defiance"] was accused of having a political message.
"What is more concerning is the reports of heavy-handed treatment of supporters, including physical assaults, with one committee member reporting she was punched as she was pushed out of the ground.
"Similar experiences have been shared with us from other supporters last night, and we've asked people to come forward so we can raise this issue with the club.
"We've already flagged it up to them and we're aware they are looking for more information.
"Clearly, though, what happened last night isn't acceptable and we will be asking both clubs and UEFA what they plan to do about it."
UEFA is reportedly aware of the problems fans had in accessing the stadium, and Liverpool are looking into the alleged incidents.
"Following detailed and troubling accounts given by Liverpool supporters attending the match against Sevilla last night, the club is seeking to establish the facts regarding their treatment at the hands of the host stewards and local police force," a club statement read.
"The safety and security of our supporters is our paramount concern and we intend to gather all the relevant information before responding further."
Liverpool drew the game 3-3 having seen a three-goal half-time lead wiped out by Sevilla.
|QB Bortles signs contract extension with Jaguars|
|Shohei Ohtani has mixed results in MLB debut|
|Mustafi wary of De Bruyne threat in EFL Cup final|
|Chumba and Dibaba reign supreme at Tokyo Marathon|
|Curry, Durant help Warriors dominate Westbrook´s Thunder|
|Coman suffers ankle injury in Bayern draw|
|I was right to turn down Man City move in 2016, says Laporte|
|Tiafoe wins two matches in a day to reach Delray Beach final|
|Navas not surprised by Ronaldo´s Benzema gesture|
|Ausilio: Contract talks with Inter´s Icardi done in silence|
|Mourinho tells McTominay to follow his heart amid international headache|
|I play for France´s biggest club – Marseille star Payet fires barb at PSG|
|Clippers owner says team traded Griffin for ´chemistry´ reasons|
|Ben Stokes returns to face New Zealand in opening ODI|
|Main priority was to win - Spalletti praises Inter´s ´heart´ after beating Benevento|
|Verdasco to meet Schwartzman in Rio Open final|
|Father fuels Conte´s fire ahead of Mourinho reunion|
|Tiger Woods shoots first sub-70 round since 2015|
|Valverde steers clear of Barcelona yellow card controversy|
|Montpellier pull clear of Racing in Top 14|
|Connacht bring Benetton back to earth|
|Butler suffers meniscus injury but Timberwolves ease ACL fears|
|Play like it´s a friendly - Guardiola reveals finals secret ahead of Arsenal clash|
|Barcelona equal record for unbeaten LaLiga run|
|Jones fronts up after Scotland smash England|
|Wales disappoint Gatland: We were the creators of our own demise|
|Inter 2 Benevento 0: Nerazzurri pick up much-needed win at San Siro|
|Barcelona 6 Girona 1: Suarez treble and Messi masterclass settle Catalan clash|
|Messi makes Girona 36th LaLiga victims to set new record|
|Nigeria demolish Rwanda in FIBA qualifying|
|Jonker shines but India still seal T20 series|
|Deeney ´not bothered´ after ending drought from open play|
|Tigers back to business after Hardaker departure|
|Championship Review: Fulham beat Wolves, Sunderland hold Boro in ill-tempered thriller|
|Lions bounce back to win, Schoeman leaves it late for Bulls|
|Russell eyes Six Nations title after inspiring Scotland to win over England|
|Watford 1 Everton 0: Stunning Deeney finish moves hosts six clear of trouble|
|Benitez rues missed chances as Newcastle lose two-goal lead|
|Heynckes ´can live´ with home Bayern draw|
|Ronaldo is a team player - Zidane hails Real Madrid star´s Benzema gesture|
|West Ham fans reference Hitler in protest at club´s owners|
|Dyche dismayed by decisions before Gabbiadini goal|
|Russell´s redemption comes as Scotland seal rare England win|
|Wagner impressed with Huddersfield´s commitment after vital win|
|No place like home for Schmidt as Ireland leave it late to sink Wales|
|Liverpool win had everything – Klopp enthuses over West Ham´s Anfield rout|
|Khachanov sets up Pouille final after Berdych upset|
|Dunk equals record for own goals in a single Premier League season|
|Chiefs return to winning ways in thriller|
|Real Madrid 4 Alaves 0: Ronaldo at the double as ´BBC´ delight|
|Burnley 1 Southampton 1: Gabbiadini grabs late leveller|
|Brighton and Hove Albion 4 Swansea City 1: Two-goal Murray helps end Swans´ unbeaten run|
|Bournemouth 2 Newcastle United 2: Hosts in thrilling fightback after Gayle double|
|West Brom 1 Huddersfield Town 2: Van La Parra and Mounie seal vital win|
|Liverpool 4 West Ham 1: Salah nets again as Reds climb to second|
|Svitolina retains Dubai crown as Kasatkina runs out of steam|
|Ill Neymar included in PSG squad for Le Classique|
|Bayern Munich 0 Hertha Berlin 0: Lewandowski´s run ends as leaders are held at home|
|Ireland see off Wales in Dublin thriller to stay perfect|
|Gattuso surprised by AC Milan´s growth since taking over|
|Lambert defends ´best goalkeeper in Britain´ Butland after own goal error|
|Stokes expected to face Black Caps|
|Mkhitaryan, Ozil potential excites Mertesacker|
|A-League Review: Perth Glory in dramatic win, Melbourne Victory end losing streak|
|Leicester City 1 Stoke City 1: Butland howler costs Potters|
|Matic insists Man Utd can still do ´big things´|
|Fisher´s birdie streak secures share of Qatar Masters lead|
|Chinese Super League transfer window makes Simeone ´uncomfortable´|
|Ingolstadt score bizarre tap-in after Duisburg goalkeeper goes AWOL|
|Allegri cautious over Dybala fitness despite Higuain injury|