UEFA has charged the Croatian Football Federation (HNS) for a second time over the behaviour of its fans - including for the display of racist banners and symbols.
The HNS has already been fined €80,000 by UEFA for similar incidents during the Group C game with Italy last week, and it is now likely UEFA will dish out a heavier penalty for a repeat offence.
As well as issuing the new charges for the conduct of Croatia's fans in Monday's match with Spain, UEFA has also opened a case against the HNS for the behaviour of its players in the game, which they lost 1-0 due to a disputed late goal which also knocked them out of Euro 2012. The case will be dealt with on Sunday, June 24.
A 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)."
UEFA has already punished the HNS for offences which included the racist abuse of Italy striker Mario Balotelli. Croatian football's governing body labelled their misbehaving fans "deviant".
The HNS has already been fined €25,000 for two offences related to the setting-off and throwing of fireworks by supporters, and also the invasion of the pitch by a supporter during the victory against Ireland.