A Gay Pride Parade in Croatia ended in violence on Saturday, the AP reported.

The news service is reporting that participants were pelted with rocks, bottles and firecrackers.

Police in the city of Split detained at least 100 people people and many others were injured. The violence brought the march to an end.

The roughly 200 people that participated in the parade were dwarfed by the thousands who lined up behind iron fences to protest the march, titled Different Families, Same Rights.

“It is a disgrace that the police failed to adequately protect participants of today's march,” said Nicola Duckworth, Amnesty International's director for Europe and Central Asia.

“The authorities must hold an immediate investigation into what happened,” he added. “The police have to make absolutely clear that discriminatory violence is a criminal offense and will not be tolerated.”

Duckworth went on to call on lawmakers to condemn the violence.

“The Croatian authorities need to act to stop this happening in [the] future. A first step would be for all political leaders to state unequivocally that everyone has the right to peacefully demonstrate and express their identity.”

At least one Gay Pride participant was taken to the hospital.

The attack comes a day after Croatia was approved to join the European Union in 2013.