UEFA have brought charges after at least 10 flares were lobbed from the Croatian corner of the Saint-Etienne stadium during the 2-2 draw with Czech Republic on Friday.
The incident sparked outrage in the Balkan nation with Croatia coach Ante Cacic branding the perpetrators “sports terrorists” and President Kolinda Grabar-Kitarovic describing them as “enemies of Croatia”.
The “Torcida Split 1950” supporters' group posted a layout of the stadium in Bordeaux where Croatia play against Spain on Tuesday and their supposed plan of action. A caption on the map spoke of “another plan”.
Angry comments under the post read “you are a disgrace to this country” and “you should be ashamed and thanks to hooligans like you I'm ashamed of being a Croatian”.
Just hours before the start of the troubled match against the Czechs, Torcida had posted a similar map of the layout of the Saint-Etienne stadium.
UEFA has opened disciplinary proceedings into the crowd trouble with a ruling expected on Monday.
Croatia's football federation (HNS) insisted that UEFA and French police had been warned that hooligans planned to disrupt the match.
HNS said it believed the Hajduk Split fans were behind the incident, but the group has rejected the accusations as “fake and unfounded”.
Croatian football fans have a history of throwing flares at matches and chanting pro-Nazi slogans.
Ahead of Euro 2016, Croatian police sent a list of 326 potential troublemakers to France.
Apart from Hajduk Split, hardcore fans are also linked with reigning Croatian champions Dinamo Zagreb.
Hooliganism has increased in Croatia over the past four years since former international striker Davor Suker took over as HNS president.
Some fans believe Suker and the federation are too closely linked with controversial former Dinamo Zagreb boss Zdravko Mamic, a key figure in Croatian football.
They accuse Mamic, indicted in April in a multi-million-euro corruption case, of unfairly profiting from football and have staged protests against the national team in response.