Following Croatia's 2-2 with Albania on Wednesday, Jovan Surbatovic, general secretary of the Football Association of Serbia (FSS), said they had submitted a formal complaint to UEFA, claiming that the two sets of fans had chanted "Kill, kill, kill the Serb" during the match.
He even indicated that the FSS would be prepared to withdraw from Euro 2024 if UEFA, who govern European football, fail to take what they see as sufficient action.
"What happened is scandalous and we will ask UEFA for sanctions, even if it means not continuing the competition," he said. "If UEFA doesn't punish them, we will think about how to proceed."
The comments came hours before Serbia's second match, against Slovenia, was set to kick off in Munich on Thursday.
Earlier, UEFA charged the FSS after Serbian supporters displayed a "provocative" banner and for throwing objects inside the stadium.
That charge had come after the Kosovo Football Federation complained to UEFA about "Serbian fans displaying political, chauvinistic, and racist messages against Kosovo" during their 1-0 defeat by England.Kosovo did not qualify for Euro 2024.
Surbatovic described the offense as an "isolated case."
UEFA's Control, Ethics and Disciplinary Body (CEDB) fined the FSS €10,000 ($10,700) on Wednesday for "transmitting a provocative message not fit for a sports event" during the game against England.
Photos of the crowd at Sunday's match show a Serbian flag in an outline of a map of the country incorporating Kosovo and including the words "nema predaje" (no surrender). Kosovo declared its independence from Serbia in 2008, but Belgrade does not recognize it as a separate state, still regarding the former province as part of its territory.
The FSS were also fined €4,500 due to objects being thrown onto the pitch by fans.
Allegations of racist chants
UK media outlets have also reported that monkey noises were made in the direction of black players during England's 1-0 win against Serbia. UEFA has said it was investigating the alleged incident.
Meanwhile, UEFA has also fined the Albanian Football Federation a total of €27,375 for the lightning of fireworks, objects being thrown, and a pitch invasion following their team's 2-1 defeat to Italy on Saturday.
Kosovo journalist barred from tournament
In a separate decision, UEFA have cancelled the media credentials of Kosovar journalist Arlind Sadiku for the tournament, after the FSS asked for his removal for seeking to provoke Serbian fans by making a double-headed eagle gesture with his hands.
The gesture symbolizes the two-headed eagle on Albania's national flag, which can stir up nationalist tensions between Serbians and ethnic Albanians, who make up the vast majority of Kosovo's population.
"UEFA can confirm that one journalist has had his accreditation cancelled due to misconduct at the UEFA EURO 2024 match between Serbia and England on 16 June 2024," the organization said in a statement.
pfd/mp (Reuters, dpa)