A photograph that was circulated on social media of a group of Dinamo Zagreb fans holding lighted flares and a banner with an obscene anti-Serb slogan has provoked outrage.
"There does not seem to be a rock bottom," Dario Brentin, associated researcher from the University of Graz in Austria, an expert on sport and nationalism in Croatia, wrote on Twitter on Friday.
The World Jewish Congress, an international organisation representing Jewish communities, praised on Monday the Austrian parliament's adoption of a proposed ban on the annual commemoration of the killings of Croatian Nazi-allied troops and civilians at Bleiburg in Austria by the Yugoslav Partisans at the end of World War II.
Similar clubs operate across Australia, gathering places for more than 43,000 Croatian-born Australians and more than 133,000 others who claim Croatian ancestry.
Tens of thousands of Croats migrated to Australia after World War Two and the collapse of the NDH, when Croatia became part of the socialist Yugoslav federation under Josip Broz Tito.
Croatian Ombudsperson Lora Vidovic on Tuesday said that if police failed to initiate legal action against former members of a paramilitary unit, who on Monday celebrated the anniversary of Operation Storm by chanting the Fascist slogan "Za dom spremni", it will be a blatant violation of the legal order.