Democratic candidate for New York City mayor, Zohran Mamdani, delivers remarks while campaigning at the Hanson Place Seventh-Day Adventist Church in the Brooklyn borough of New York City, US, Nov. 1, 2025. Photo: REUTERS/Ryan Murphy

A New York Jewish educators’ leader warned that Mayor Zohran Mamdani’s rhetoric could contribute to hostility against Jewish institutions as the mayor issued a Tisha B’Av message that omitted the holiday’s historical connection to Jerusalem and the destruction of the two Jewish Temples.

Moshe Spern, president of United Jewish Teachers, urged the New York Police Department to increase security around synagogues, schools, camps and other Jewish facilities during the fast day.

“Many of us are deeply concerned that this statement, combined with the current climate, could incite further hostility or targeting of Jewish institutions,” Spern wrote.

His warning followed a video in which Mamdani attacked Israeli Prime Minister Benjamin Netanyahu, accused him of “genocide” and said city attorneys had explored whether New York could execute the International Criminal Court’s arrest warrant against the Israeli leader.

Mamdani acknowledged that he did not possess the legal authority to arrest Netanyahu.

On Wednesday, the mayor issued a separate message marking Tisha B’Av.

“Wishing a peaceful Tisha B’Av to Jewish New Yorkers across the five boroughs,” Mamdani wrote. “From sundown tonight until tomorrow, mourners will pause and reflect on the history and resiliency of the Jewish people. May all observing have a safe and meaningful fast.”

Observers noted that the statement did not mention Jerusalem or the destruction of the First and Second Temples, the central events commemorated on Tisha B’Av.

The fast day marks the destruction of the First Temple by the Babylonians and the Second Temple by the Romans, both in Jerusalem. It is one of the most solemn days on the Jewish calendar.

Mamdani’s latest comments about Netanyahu revived one of the most controversial promises from his 2025 mayoral campaign.

While running for office, the far-left democratic socialist repeatedly said he would seek to have Netanyahu arrested if the prime minister visited New York, including to attend the annual United Nations General Assembly.

The issue returned to the foreground last week, when Mamdani told The New York Times that his administration remained in “active conversation” with the city’s Law Department about the possibility of arresting Netanyahu.

“I believe that Prime Minister Netanyahu belongs in The Hague,” Mamdani said. “He’s a war criminal who has been charged by the International Criminal Court.”

In his subsequent video, Mamdani said city attorneys had reviewed “every avenue available under applicable law” before determining that the city lacked the authority to execute the ICC warrant.

President Donald Trump responded Monday by declaring that Netanyahu “will not be arrested, in any way, shape, or form, while in the United States of America.”

Trump defended Netanyahu as an American ally fighting Iran and rejected Mamdani’s renewed pursuit of his campaign promise.

Mamdani’s repeated threats to arrest Netanyahu and his accusations that Israel is committing “genocide” in Gaza have drawn backlash from members of New York’s Jewish community.

Spern urged the NYPD to “immediately implement heightened patrols and visible security presence around all Jewish synagogues, schools, camps, and related facilities” during Tisha B’Av.

The ICC issued arrest warrants for Netanyahu and former Israeli Defense Minister Yoav Gallant in November 2024, alleging reasonable grounds to believe that they bore criminal responsibility for the war crime of using starvation as a method of warfare and crimes against humanity including murder and persecution.

Israel has vehemently rejected the charges, arguing that the court lacks jurisdiction, disregarded Israel’s independent judicial system and distorted the conduct of a defensive war launched after the Hamas-led massacre across southern Israel on Oct. 7, 2023.

Israeli and American officials have also accused the ICC of drawing a false moral equivalence between the elected leaders of a democratic state and Hamas terrorists who murdered approximately 1,200 people and abducted 251 others.