Inter Milan forward Romelu Lukaku has said he was subjected to racist abuse in the 3-1 Champions League victory at Slavia Prague on Wednesday.
The Belgium international appeared to report the abuse to the official in the first half after scoring a goal which was subsequently disallowed.
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"I said this the last time I was with the Belgian national team, UEFA should do something to solve this problem because situations like this in a stadium are not right," he told Esporte Interativo.
"During the match it happened twice to me and it's not OK. It's 2019, there are many players from various nationalities in the teams and when people go to the stadium and behave wrongly in my view they are a negative example for children.
"I hope UEFA now does something, because all the stadium behaved like this after Lautaro [Martinez]'s first goal and that's not good for the people watching the game."
Lukaku scored one goal and saw another ruled out via the VAR in the match which saw Inter leapfrog Borussia Dortmund into second place in the group with one match remaining.
However, on Friday Slavia Prague denied there had been racist chanting and called on Lukaku to apologise.
"We must reject that there has been racist chanting of the whole stadium," the club tweeted. "We analysed available footages, and none confirmed Mr Lukaku's statement.
"The club has already apologised for individuals' behaviour and it would be appropriate for Mr Lukaku to apologise for his words too."
The 26-year-old was subjected to monkey chants against Cagliari in September and he called for Italy to do more to combat racism.
There have been a number of racism incidents in football this season with Serie A players Mario Balotelli and Kalidou Koulibaly subjected to abuse from the stands, while Marcus Rashford, Paul Pogba and Tammy Abraham have been abused on social media.