We are working on it, it's a very difficult job given the time that has passed, but we are working and won't give up, said Karamarko.

Asked if there was resistance in Croatia to the investigation of such crimes, he said, "Absolutely. I would be lying if I said it didn't exist."

Resistance to investigations comes from part of the public who wrongly interpret them as an attack on anti-fascism, which is untrue, he said. "We aren't dealing with any ideologies, either with fascism, anti-fascism, communism, anti-communism or with crimes that have been committed and for which nobody has answered. Crimes have no ideology. Our duty is to detect and define the perpetrator as well as the existing objective responsibility."

Asked to comment on the Austrian police ban on any displays of Ustasha insignia or any photos of Croatian army general Ante Gotovina at the commemoration, Karamarko said he did not know what the Austrian police had banned.

"I am totally against glorifying the insignia of totalitarian regimes. It is paradoxical that 60 years after World War Two such insignia are still appearing, but people are also irritated by the red star under which the (former Yugoslav army) destroyed Vukovar and committed crimes in Croatia," he said.

Karamarko was speaking to the press before a commemoration on the 66th anniversary of the Bleiburg killings and the Way of the Cross marches in Bleiburg field.

The commemoration is held annually in honour of fleeing Croatian soldiers and civilians who were handed over by allied forces to Tito's Partisans in Austria at the end of the WW2. Thousands of them were killed by the Partisans without a trial at Bleiburg field and during death marches back to Yugoslavia known as Way of the Cross marches.