A man wearing a HOS t-shirt at today's commemoration in Zadar (Photo: HRT) A man wearing a HOS t-shirt at today's commemoration in Zadar (Photo: HRT)

As the Commander-in-Chief, Milanović also ordered top military officials not to participate in the commemoration as well. He described the incident as unacceptable.

"After it was noticed that among the participants in the ceremony there were people who were displaying Ustasha insignia and their slogan, the President of the Republic called and warned the Prime Minister that this was unacceptable. Since it was subsequently established that persons wearing Ustasha insignia and their slogan also were participating in the official protocol of the commemoration, the President of the Republic canceled his attendance at the event,” said an official statement issued by the Office of the President.

Asked about the incident, Prime Minister Andrej Plenković told reporters that he heard about what happened from the President in a phone call early this morning.

“As far as I understood, several people wearing HOS t-shirts showed up, who according to Minister Banožić, were not in the official protocol related to the veterans groups that were participating. I don't know whether it happened that way. Whatever the case may be, I prefer commemorations to provocations,” Plenković said.

This is the second time the President has walked out of an event over the same issue. Last year, Milanović abruptly left a ceremony marking the anniversary of the 1995 Operation Flash in Okučani, after seeing persons who were participating in the official part of the even were wearing t-shirts with the Ustasha salute and other Ustasha insignia. "For the homeland ready", the Ustasha salute, was used in Nazi-allied Independent State of Croatia during WWII.