- Croatian Football Federation in trouble over fan behavior for third time at Euro 2012
- UEFA investigating "display of racist banners and symbols" during match against Spain
- Croatia was already fined on Monday after fans racially abused Italy's Mario Balotelli
- Croatian FA also punished after supporters let off flares during match against Republic of Ireland
European football's governing body has opened fresh disciplinary proceedings against Croatia over alleged racist behavior by its supporters during a Euro 2012 match against Spain.
UEFA cited the "improper conduct of supporters (display of racist banners and symbols)" by Croatia fans during the game in Gdansk on Monday.
Croatia, which was eliminated from Euro 2012 after losing the match 1-0, has already been admonished twice during Euro 2012 over the conduct of its fans.
Wednesday's Uefa statement read: "Uefa has today opened disciplinary proceedings against the Croatian Football Federation (HNS) for the setting-off and throwing of fireworks, and the improper conduct of supporters (display of racist banners and symbols) at the EURO 2012 Group C match against Spain in Gdansk on Monday.
"The disciplinary case also involves the improper conduct of the team (six Croatian players received a yellow card during the match)."
The UEFA Control and Disciplinary Body will deal with the case on Sunday, it said.
Croatia was fined 80,000 Euros on Monday after Italy striker Mario Balotelli was racially abused by fans during a previous match.
And last week, the HNS was fined after supporters let off flares during the game against Republic of Ireland.
The issue of racism has threatened to mar Euro 2012, which is being co-hosted by Poland and Ukraine.
Members of the Dutch squad claimed to hear monkey noises during an open training session in Krakow, Poland, before the tournament started, though the Dutch FA opted not to lodge an official complaint with UEFA.
In addition, family members of two black English players chose not to travel to the competition for fear of being subjected to racism.
UEFA has already taken the step of writing a letter to the mayors of each host city asking for a zero-tolerance approach to racist abuse.
Uefa also fined England's Football Association 5,000 Euros on Wednesday over the "inappropriate conduct" of fans in last week's Euro 2012 match against Sweden.
The fine related to an attempted pitch invasion by English supporters after England won the match in Kiev, Ukraine.