Video emerged of a fan racially abusing Napoli's Kalidou Koulibaly during the first leg of the Europa League quarterfinals in London.
Arsenal have launched an investigation into a video which has emerged on social media allegedly showing a supporter directing racist abuse towards Napoli's Kalidou Koulibaly.
The video was taken by a fan inside the Emirates Stadium on Thursday during Arsenal's 2-0 win over Napoli in the first leg of their Europa League quarterfinal, and appears to show the fan hurling abuse at the Senegalese defender.
The statement read: "We utterly condemn use of this type of racist language and have launched an investigation to identify the culprit.
"We operate a zero tolerance approach, and anyone behaving like this is not welcome at Arsenal and will be banned from matches.
"We have an extremely diverse community of fans who are all part of the Arsenal family and such incidents are rare at Emirates Stadium. We encourage supporters to report any incidents as they happen to stewards or via our matchday alert service."
Koulibaly played the entire 90 minutes of Thursday's game, but was powerless to prevent his side falling to a 2-0 loss. It was his deflection which took Lucas Torreira's effort past Alex Meret for the Gunners' second goal, and Napoli now have a huge mountain to climb if they are to reach the semifinal.
Aaron Ramsey's early goal gifted Arsenal a deserved advantage, and Torreira's deflected effort ensured Unai Emery's men picked up a crucial victory, as they seek to win the Europa League and secure qualification for next season's Champions League.