A photo of Indonesia's new 100,000 rupiah bill. The leader of an Islamist militant groups says the small circular Bank Indonesia logo resembles a hammer-and-sickle, a symbol of communism. (Vincent Bevins for The Washington Post)

JAKARTA, Indonesia — Religious radicals in Indonesia are clashing with the government after a cleric claimed he could see communist imagery hidden on the country's new currency.

Habib Rizieq, the leader of the militant Islamic Defenders Front (FPI) recorded comments last month in which he claimed new Indonesian rupiah notes carry the hammer-and-sickle, an iconic symbol of communism. On the notes, the letters B and I (for “Bank Indonesia”) overlap in a way that vaguely recalls the communist logo — if you squint hard enough.

This may seem like a trivial dispute, but it's a provocative attack in the world's most populous Muslim nation, where hundreds of thousands of people (or more) were killed in the 1960s for being communists or suspected communists.

In 1965 and 1966, members of the military, along with civilians, systematically executed members of the Indonesian Communist Party (PKI) as well as many of its alleged supporters. The PKI had been accused of backing a military coup. In the decades of authoritarian rule that followed, communists continued to be portrayed as an evil, dangerous threat. When current President Joko “Jokowi” Widodo was elected in 2014, activists hoped he would apologize for the massacres or launch an official investigation. But Islamists, who still see secular leftism as a major problem, strongly opposed the idea, and Widodo took no major action.

Communist parties are still illegal in Indonesia, and Rizieq was questioned Monday by the police, who were investigating whether he slandered the bank by even making the claim.

Some members of the FPI assembled outside the police station to support Rizieq. The Islamist organization is notorious for carrying out violent raids against people it deems are committing un-Islamic acts.

“There is a deep strain of anti-communism, particularly in the Muslim community, and it was made even more intense by the executions in the 1960s,” said Gregory Fealy, a professor at Australian National University who has worked on politics and Islam in Indonesia. “There continues to be conspiracies theorizing about the reemergence of communists, a lot of which are very fanciful, but they can really get people's imaginations going.”

Fealy said accusations of crypto-communism are fairly common for Rizieq's group. “This is de rigeur for the FPI,” he said. “Whether they believe there was really communist imagery there or not, they know this always will get a reaction.”

But Rizieq's claim puzzled many Indonesians, who couldn't see the hammer-and-sickle no matter how hard they tried.

Gandrasta Bangko, a 35-year old marketing director in Jakarta, took to social media to mock the allegation. “Just saw a cloud formation that looks like Palu-Arit,” he tweeted, using the Indonesian term for hammer-and-sickle. “Preparing lawyer team to sue anyone responsible for this s---.”

An unsigned editorial published Tuesday in Indonesia's Tempo magazine said that “we can rightly accuse Rizieq of suffering from acute communism-phobia. It is more laughable than criminal.” The editorial argued that rather than focusing on absurd debates over phantom imagery, the group should be restrained by being held responsible for their actual crimes.

After speaking with police, Rizieq denied that he had improperly accused the government of communism — but still didn't back down on his claim that the bills have threatening imagery.