Masuod Shojai-Tabatabai, the secretary of the contest, said today, that they have no interest in denying the Holocaust or "ridiculing its victims."
He added that the world was witnessing a similar massacre "by the Zionist regime in Gaza and Palestine."
Some 150 works from 50 countries are on display. The works mainly criticise what they consider the use of the Holocaust by Israel to distract from the Palestine issue.
Cartoonists from various countries, including France, are competing in the contest which is organised by non-governmental bodies with strong support from Iran's hard-liners.