"In this camp alone a population equalling more than half our country's was killed consciously, something that could only have happened because of a total moral disaster, loss of every moral compass," Pahor said ahead of the ceremony, attended by some 300 survivors and senior officials of wartime Allies.

"Living witnesses of the horrors are with us today. And they are not silent witnesses. They can testify to the horrors and we must hear them out and act," Pahor said, arguing that even though it seemed today that it was possible to avoid war, it was necessary to actively work for peace.

Before attending the commemoration, which also saw attendance by Red Army veterans who liberated the camp, Pahor lit a candle in memory of the victims at a memorial plaque that since 2008 also bears an inscription in the Slovenian language, according to a release from his office.

Pahor was accompanied by four Auschwitz survivors, a representative of stolen children who survived the camp and a representative of the Jewish Community of Slovenia, the son of a camp prisoner Luka Woititz. Of the 2,342 Slovenians imprisoned in Auschwitz, 1,331 perished there.

Commenting on the absence of Russian President Vladimir Putin at the ceremony, Pahor said that even if he could understand concerns over topical developments, it was necessary to look ahead. "Things can happen again and we need to bear that in mind," he said, pointing to violence in Ukraine, which he said Slovenia condemned.

As a series of events to commemorate the 70th anniversary of Auschwitz-Birkenau's liberation and to mark International Holocaust Remembrance Day is also being held in Slovenia. In Maribor an international academic conference remembered Jewish factory-owner Marko Rosner (1888-1969).

The event was held as part of the project Shoah - Let Us Remember 2015, which is being held under the auspices of Prime Minister Miro Cerar, and features a series of events paying tribute to all victims of the Holocaust, both those who lost their lives and the survivors.

The Maribor conference, which is held under the auspices of the Foreign Ministry and the International Holocaust Remembrance Association, was hosted by the Centre of Jewish Culture Maribor Synagogue in cooperation with the Maribor University Library.

The event discusses various topics on the history of the Holocaust in the region of the former Yugoslavia and every year the focus is on one person. This year it remembers Rosner, the central figure of the hundred-strong Maribor Jewish community before WWII.

During the war Rosner found refuge abroad and finally settled in Israel. He was a successful entrepreneur, involved in the local textile industry and was also known as a benefactor, Synagogue head Marjetka Bedrač said, adding that he also helped Jewish refugees during the war.

The symposium also discussed the Christians' attitude to the persecution of the Jews, the Jews in western Slovenia and the Nazi persecution of the Roma, among other topics.