New York — A “developing threat” to New York City’s Jewish community was averted by the arrests of two men at Penn Station — one of whom had Nazi-type insignia on him, New York City Police Department Commissioner Keechant Sewell and sources said Saturday.

Christopher Brown, 22, of Riverhead, Long Island, and Matthew Mahrer, 22, of Manhattan, were busted in the transit hub late Friday night, said police sources.

Brown, who possessed a “swastika” armband when he was caught, was charged with making terroristic threats, harassment and weapons possession, said the sources. It was unclear to the sources whether Brown was wearing the armband when he was caught.

The weapon was a large hunting knife, the sources said.

Mahrer, also 22, was charged with criminal possession of a weapon, which sources said was an illegal Glock 17 firearm.

The firearm was recovered from the Upper West Side apartment where Mahrer lives with his parents, said police. Mahrer’s mother has been “cooperative,” police sources said.

Brown and Mahrer were arrested by “sharp-eyed MTA police officers,” Sewell’s statement said. Besides the knife and gun, the pair also possessed a “30-round magazine, and several other items,” the commissioner said.

The threat by the two men was uncovered Friday by state and federal law enforcement, Sewell said.

Authorities “moved swiftly to gather information, identify those behind it, and operationally neutralize their ability to do harm,” Sewell’s statement said.

What Brown and Mahrer intended to do with their weapons was not made clear in the statement.

Police commanders are “strategically deploying assets at sensitive locations throughout New York City,” Sewell said.

A police bulletin issued Friday and posted to Twitter on Saturday by City Council member Ari Kagan, D-Brooklyn, identified Brown as a suspect, and said he has a history of mental illness. Brown had threatened synagogues in the New York area, the bulletin said.

Police officers were present Saturday evening at the Upper West Side building where Mahrer lives with his parents.

“This is very bad, very bad news,” said a woman who lives in the building and asked to remain anonymous.

“I don’t feel safe about this, having a Nazi in this building. You never know what is going to happen,” the woman said.

Saturday’s arrests come weeks after the FBI said it had “credible information of a broad threat to synagogues" in New Jersey, prompting New York City Mayor Eric Adams to announce that NYPD officers were sent to Jewish communities and houses of worship “out of an abundance of caution.”

New Jersey federal agents on Nov. 10 arrested Sayreville, New Jersey, resident Omar Alkattoul, 18, on federal charges of making a threat to attack a synagogue “based on his hatred of Jews.”

Celebrities’ writing and social media activity have amplified a number of antisemitic incidents in recent months.

Brooklyn Nets star Kyrie Irving was suspended over his social media postings of a documentary laced with antisemitic rhetoric, and Kanye West’s anti-Jewish posts on Twitter and Instagram cost him endorsement deals with Adidas and other companies.

Antisemites have cited West’s musings in their propaganda, the Anti-Defamation League reports. For example, flyers saying “Kanye 2024″ were distributed in Rhode Island last week, the group said.

“Antisemitic incidents have been on the rise in the United States over the past number of years, with 90% of American Jews saying that antisemitism is a problem,” said Myra Clark-Siegel, a spokeswoman for the American Jewish Committee.

“Antisemitism is not a problem only for the Jewish community to address; we must all stand up to hate,” Clark-Siegel said. “We want to thank law enforcement for their quick response that thankfully averted what could have been a dangerous and serious situation.”