Tottenham Hotspur manager Andre Villas-Boas has demanded action from Uefa after claims his players were racially abused by a section of Inter Milan fans during the 4-1 defeat at the San Siro on Thursday.
An inflatable banana was reportedly passed through the crowd during the match, which saw Spurs eventually prevail on away goals after extra time.
Villas-Boas also claims he could hear chants being directed at Tottenham's black players from the stands.
"It was very, very easy to hear the chanting so I am sure that Uefa will act on it," he told BBC Sport.
"It's difficult for Inter because it is something that has happened before.
"It doesn't mar the game but it is something that should have been avoided," the manager added.
Inter fans were fined £50,000 after supporters were found to have abused former striker Mario Balotelli in February's Milan derby.
Lazio were fined a total of €140,000 and ordered to play one match behind closed doors in January, after racial incidents in the Europa League group games against Tottenham and Maribor, a fine which also punished the use of fireworks and missiles by supporters.
Uefa have been regularly criticised for their attitude towards racism, with fines often preferred to bans and points deductions. Former Tottenham captain Sol Campbell last year was among those demanding the governing body took a harsher line on racial incidents.
Antonio Cassano, Rodrigo Palacacio and William Gallas' own goal threatened to undo all of Tottenham's good work from the first leg, taking the game into extra time in the Italian capital.
But Emmanuel Adebayor struck a crucial away goal, pouncing after Samir Handanovic had parried Moussa Dembele's shot, and despite Ricardo Alvarez netting with 20 minutes left, the north Londoners held out to book their place in the last eight.