Organizers have said the cartoon contest does not attempt to "confirm or deny" the Holocaust, but rather highlight a "new Holocaust" against Palestinians. The Iranian government has distanced itself from the exhibit.
An anti-Israel cartoon contest opened in Tehran on Saturday, with many entries ridiculing Israeli Prime Minister Benjamin Netanyahu and criticizing Israel's policy towards the Palestinians.
The exhibition of 150 cartoons from 50 countries was opened on the eve of when Palestinians commemorate the "Nakba," Arabic for "catastrophe," the same day as Israel's independence in 1948.
Among the entries are cartoons depicting Netanyahu as Adolf Hitler and another of a coffin with a Holocaust inscription replacing Israel on the map as it crushes Palestinians.
Organizers said the exhibit was opened to highlight Israel's misuse of the Holocaust for political ends and the "new Holocaust" being committed against Palestinians.
"We are not seeking to confirm or deny the Holocaust," said organizer Massoud Shojaie Tabatabaei while opening the event, adding he respected the victims of the Holocaust. "Jews who lost their lives in the Holocaust were subject to oppression by Nazis.
"Holocaust means mass killing," Tabatabaei noted. "We are witnessing the biggest killings by the Zionist regime in Gaza and Palestine."
Himself a cartoonist, he said the exhibition was in response to Western countries allowing negative depictions of the Prophet Mohammed in cartoons.
Iran has repeatedly criticized negative cartoons about the Prophet published in the West.
Tabatabaei said there was a "double standard" in the West when it comes to free speech. Holocaust revisionism or denial as well as hate speech are illegal in some European countries.
A total of $50,000 in prize money will be split among 16 finalists, with the winner receiving $12,000. The exhibit is organized by the Iranian House of Cartoon gallery and on display from May 15-30.
World Jewish Congress President Ronald Lauder said he was "disgusted" that Iran was holding a competition "showcasing cartoons denying and mocking the Holocaust."
The Iranian government has distanced itself from the cartoon exhibit.
Foreign Minister Mohammad Javad Zarif said in an April interview with "New Yorker" magazine the contest was organized by a nongovernmental organization without any support from the authorities.
Questioned about why the government allowed such contests, Zarif asked why the racist Ku Klux Klan exists in the United States.
"Is the government of the United States responsible for the fact that there are racially hateful organizations in the United States? Don't consider Iran a monolith. The Iranian government does not support, nor does it organize, any cartoon festival of the nature that you're talking about."
Iran came under heat in 2006 for holding a Holocaust conference the Foreign Ministry said was meant to provide an open debate on history. Critics dubbed it a Holocaust denial conference.
Reformist President Hassan Rouhani has said the Holocaust was a tragic event that Iran also condemns.
cw/sms (AFP, AP, dpa)