Several thousand Croatian supporters crowded into an area around in Poznan's main old town square, drinking and singing before the Group C game in the evening. Some men were bare chested, displaying tattoos of nationalist symbols.
Some set off flares. Police monitored the situation, but did not intervene.
In 2011, a Hague tribunal sentenced Gotovina to 24 years in prison for his role in a 1995 military offensive intended to drive Serb rebels out of land they had occupied for years along Croatia's southern border with Bosnia.