FIFA has opened disciplinary proceedings against Switzerland players Xherdan Shaqiri and Granit Xhaka, looking into their goal celebrations during Friday's 2-1 win over Serbia at the World Cup.
Both players, who are ethnic Albanians and of Kosovar heritage, celebrated after scoring with a gesture which appeared to imitate the eagle displayed on Albania's flag.
Serbia does not recognise the independence of its former province Kosovo, which broke away 10 years ago and whose 1.8 million people are mostly ethnic Albanians.
The players denied that their celebration was political, though Xhaka acknowledged thinking about his heritage.
"For me, it was a really special day," said Xhaka. "This is a victory for my family, for Switzerland, Albania, Kosovo. The gesture was for everyone who has supported me; it was not aimed at our opponents. It was a really emotional game."
Shaqiri, who also wore the image a Kosovo flag on his boot, said: "It's nothing to do with politics, it's about football."
Two Swiss government ministers backed the players' actions on Sunday.
"Anyone who experiences the electric atmosphere of the game can appreciate more the performance of our national team and can understand the emotions which overcome a player," Defence, Civil Protection and Sports minister Guy Parmelin told the Neue Zurcher Zeitung (NZZ).
Swiss Foreign minister Ignazio Cassis was also sympathetic.
"I have no doubt that you can feel patriotic emotions for the land which has taken you in without forgetting your roots," he said.
FIFA's disciplinary regulations state that players found guilty of provoking the public face a two-match suspension and Swiss Football Federation president Peter Gillieron said he was hopeful that the pair would be absolved.
"It would be a hammerblow if they were to be suspended," he said.
FIFA said it had also opened proceedings against the Serbian FA for crowd disturbance and the display of political and offensive messages by Serbian fans. A preliminary FIFA investigation had been opened against Serbian coach Mladen Krstajic for "alleged statements made in the aftermath of the match," added the governing body.
Reports quoted Krstajic as telling Serbian reporters that German referee Felix Brych -- who denied his team a penalty when two defenders wrestled down striker Aleksandar Mitrovic -- should be put on trial in The Hague, home of the United Nations' war crimes tribunal for the former Yugoslavia.
It was thought that Shaqiri and Xhaka's celebrations could incite Balkan political tensions, but the day afterward many Serbs appeared angrier at the referee than the Swiss players.
"The Swiss Provocation," wrote Serb nationalist daily newspaper Vecernje Novosti alongside photographs of the gestures and a picture of Shaqiri's boots. However, Serbian newspapers gave more space to the VAR spat than to the nationalist gestures.
Serbian Football Association chief Slavisa Kokeza told the BBC that he was sending a protest to FIFA over the Mitrovic incident and complained that a German referee was assigned to a game featuring their neighbours Switzerland.
"I do not think this is only about VAR, but that the whole thing was directed by the people who appoint referees," Kokeza said. "We all know too well that more than half of Switzerland's population is German.
"Technical staff, players, people in Serbia, they are all disappointed and frustrated because of injustice some people at FIFA came up with."
Thousands of Kosovo Albanians trekked across Europe in the 1990s, fleeing rising ethnic tensions that culminated in a bloody 1998-99 war of independence between ethnic Albanians and Serb forces that left about 10,000 people dead. Many settled in Switzerland, but still have strong feelings for their homeland -- Xhaka's brother plays for the Albanian national team.
In the Kosovo capital, Pristina, fans set off flares when the Swiss players scored . Fans in the Albanian capital, Tirana, cheered as they watched the match on outdoor screens.
Kosovo's president Hashim Thaci wrote on Twitter: "Congratulations to goal scorers Xhaka, Shaqiri and entire #Switzerland on a well deserved win! Proud of you.'' He finished his tweet: "Kosova ju don!" -- an Albanian phrase meaning "Kosovo loves you!"
Thaci is due to meet his Serbian counterpart Aleksandar Vucic in Brussels on Sunday for European Union-brokered talks on their countries' strained relationship.
Albanian Prime Minister Edi Rama posted on his Facebook page photos of Shaqiri and Xhaka with their hands crossed in the two-headed eagle symbol and wrote: "Photo of the day."
Information from Reuters and The Associated Press was used in this report.