In an attack on French President Emmanuel Macron’s defense of the right to show cartoons depicting the Prophet Muhammad, which many Muslims consider disrespectful and blasphemous, Iran's supreme leader has equated Holocaust denial with perceived insults against Islam's prophet.

The remarks by Ayatollah Ali Khamenei resulted in renewed calls on Twitter to add a warning label to Khamenei’s tweets or remove his account, with some saying Iran’s top authority should not be allowed to spread "anti-Semitism" on social-media networks.

Khamenei’s October 28 comments addressed to “Young French People” were posted in Persian, French, and English on his website, as well as on social-media sites including Twitter.

In the short message, the Iranian leader said Macron’s move was a “stupid act.”

Macron has defended secular values following the killing of 47-year-old schoolteacher Samuel Paty, who was beheaded after showing cartoons of the Prophet Muhammad in his classroom after allowing any students who might be offended to leave.

Macron has paid tribute to Paty, saying he was "killed because he was teaching students about freedom of speech, the freedom to believe and to not believe."

“Ask your president why he supports insulting God’s Messenger in the name of freedom of expression. Does freedom of expression mean insulting, especially a sacred personage?” Khamenei asked. “Isn’t this stupid act an insult to the reason of the [people] who elected him?” he added.

Khamenei then compared insults against the Prophet Muhammad with Holocaust denial, which is banned in some countries, including Germany.

“Why is it a crime to raise doubts about the Holocaust? Why should anyone who writes about such doubts be imprisoned while insulting the Prophet (pbuh) is allowed?”

Khamenei’s tweets were met with criticism, including by Jonathan Greensblatt, the national director and chief executive officer of the Anti-Defamation League (ADL), who said, “Holocaust denialism is hate, pure & simple.”

“Why is Khamenei allowed to consistently espouse anti-Semitism that clearly violates Twitter policy on hate speech?” added Greensblatt, who is the grandson of a Holocaust survivor who escaped Nazi Germany.

The Simon Wiesenthal Center also blasted Khamenei’s tweet, saying, “No Ayatollah, the real question is why @Twitter gives you a free pass to use their platform to push your genocidal threats of Final Solution against the world’s largest Jewish community -- the Democratic State of Israel?”

Khamenei’s tweets coincided with a hearing by the U.S. Senate Committee on Commerce, Science, and Transportation, where Twitter Chief Executive Officer Jack Dorsey, as well as the chief executives of Facebook and Google, were questioned on issues dealing with free speech and content moderation.

At the hearing, Dorsey was asked by Republican senators why tweets by U.S. President Donald Trump have been flagged for containing “misleading or potentially harmful information” but controversial tweets by other world leaders and dictators have been not been met with action.

Senate Commerce Chairman Roger Wicker specifically asked Dorsey about four tweets by Khamenei which, he said, glorified violence. They included a tweet posted in May that said: "We will support and assist any nation or any group anywhere who opposes and fights the Zionist regime, and we do not hesitate to say this."

Iranian officials refer to Israel as the Zionist regime. The Islamic republic, home to the Middle East’s largest population of Jews outside of Israel, does not recognize Israel.

“We did not find those to violate our terms of service because we consider them saber-rattling, which is part of the speech of world leaders in concert with other countries,” Dorsey responded.

“Speech against our own people or a country’s own citizens we believe is different and can cause more immediate harm,” Dorsey added.

In 2019, Khamenei’s Twitter account was temporarily banned for reiterating a fatwa issued by the founder of the Islamic republic, Ayatollah Ruhollah Khomeini, against author Salman Rushdie.

“Imam Khomeini’s verdict regarding Salman Rushdie is based on divine verses and just like divine verses, it is solid and irrevocable,” the tweet posted by @Khamenei_ir had said.

A Twitter spokesman said then that the tweet violated the platform’s rules.

“It’s against our rules to make specific threats of violence or wish for the serious physical harm, death, or disease of an individual or group of people,” the spokesman said then.

Khamenei’s Twitter account was reactivated after the tweet's removal.

In the past, some critics have suggested that Khamenei and other Iranian officials should not be allowed to use Twitter as long as it remains blocked inside the country.

Others say Twitter is one of the few platforms where Iranians can challenge and criticize comments by their leaders, including Khamenei, criticism of whom is considered a red line in Iran that has landed many in prison.

One such reaction came on October 28 from former political prisoner Zia Nabavi, who spent nearly nine years in prison after being arrested following the disputed 2009 presidential election and a brutal state crackdown that followed.

“You cannot give guidance on freedom of expression in France when your [own] criticism in your country can result in two years in prison,” Nabavi said, without naming Khamenei.