Football officials in Kosovo called for action after the banner was displayed in the Serbian team's locker room
FIFA has launched disciplinary proceedings against Serbia after complaints from football officials in Kosovo about a flag displayed in the Serbian team's locker room at the World Cup in Qatar.
The banner was shown prior to Serbia's game against Brazil on Thursday, and featured an outline of Kosovo with the colors of the Serbian flag across it. The slogan "no surrender" was written on the banner.
Officials at the Football Federation of Kosovo (FFK) demanded that FIFA take action, accusing the Serbian team of an "aggressive act contrary to the values that football transmits."
FIFA confirmed in a statement on Saturday that its disciplinary committee had opened proceedings, citing a section of its code which covers "offensive gestures, signs or language" and "using a sports event for demonstrations of a non-sporting nature."
No timeframe was initially given for a decision on the matter.
Serbia lost their opening game 2-0 against Brazil, and next play Cameroon on Monday. Their final Group G game is against Switzerland on Friday.
Kosovo is a province of Serbia which was occupied by NATO after its 1999 bombing campaign. Its ethnic Albanian provisional government declared independence with US backing in 2008.
While the EU has urged Belgrade to recognize Kosovo's independence, Serbia has vehemently declined to do so. Russia is among the countries which do not recognize the region as a separate state.
Kosovo became a FIFA member in 2016, and political rows involving the area have spilled over into football in the past.
Swiss players Granit Xhaka and Xherdan Shaqiri - both of whom are ethnic Albanians - were fined by FIFA after making the 'double-headed eagle' salute during a World Cup match against Serbia in Russia four years ago.
The gesture was seen as a reference to the eagle on the Albanian flag.
The current row comes amid tensions between Serbia and its breakaway province over the license plates used by vehicles. An EU-brokered deal was reached on the matter in Brussels earlier this week.