(CNN) -- European football's governing body fined Germany's national soccer body €25,000 ($31,000) Tuesday over what witnesses say was the display of neo-Nazi symbols by German fans at a Euro 2012 match.
The "improper conduct of supporters" occurred when Germany beat Denmark 2-1 in a Group B match in the Ukrainian city of Lviv on June 17, UEFA said.
The anti-discrimination organization FARE stated on its official Twitter page: "FARE can confirm that one of our observers reported a neo-Nazi banner in the German section at the match v. Denmark in Lviv on Sunday."
German newspaper Taz also highlighted the wearing of neo-Nazi symbols by fans.
After the game, UEFA said it was investigating "the setting-off of fireworks and the improper conduct of supporters (display of inappropriate banners and symbols, and inappropriate chanting)."
The German Football Association has a day in which to lodge an appeal.
Germany is not the only nation to face scrutiny from UEFA over the actions of its supporters at the Euro 2012 tournament, which is being jointly hosted by Ukraine and Poland.
New investigations were opened Tuesday into Russia and Spain after alleged racist behavior and chanting by fans. UEFA's disciplinary body is due to report back on Thursday.
Russia and Croatia have already been fined tens of thousands of euros for poor behavior by their supporters.