Sabbath services just began at Central Synagogue on Friday night when prayers were interrupted by a crashing sound. Shouts rang out. Congregants held their breath.

It was a scenario that Jewish New Yorkers have come to fear when they go to synagogue, passing through metal detectors before they pray. Worshipers had filled the pews of the prominent Upper East Side synagogue to welcome the Sabbath, when a man screamed obscenities and struck a congregant. As security escorted out the assailant, identified as 46-year-old Larry Montes, the rabbi instructed everyone to breathe and began, again, to pray.

Angela Buchdahl, the senior rabbi of the community, was away for a family event, but praised other members of the clergy for comforting the congregants, continuing prayers and delivering a sermon that addressed the tension in the room.

“We know what kind of city we want to live in,” said Rabbi Buchdahl in an interview Saturday. “One in which people of all faiths, classes, and colors feel belonging. For Jewish New Yorkers, it has to include both safety and security on a physical level, and knowing we will not be demonized, marginalized or harassed for supporting a Jewish homeland.”

News of the attack at Central Synagogue reached New York City’s Jews as they contend with threats, fears and internal divides. Jews across the city were already shaken by the recent stabbing of a Jewish man on the Upper West Side, who was leaving synagogue services during a day of mourning. Hate crimes in New York City have been on the rise in recent years. By the start of August, the police department recorded 360 hate crimes this year, 205 of which were targeting Jewish people.

“This was a horrible attack in Central Synagogue yesterday evening,” Mayor Zohran Mamdani told reporters on Saturday. “Jewish New Yorkers should be able to go to their synagogue without having to fear for their lives.”

City Hall said both the mayor and the head of the Mayor’s Office to Combat Antisemitism reached out to Rabbi Buchdahl. Mr. Mamdani has faced calls to tone down and bring more nuance to the way he criticizes Israel, particularly after he released a video that urged federal authorities to arrest the country’s prime minister, Benjamin Netanyahu.

Mr. Mamdani has said he is committed to protecting New York’s Jews and believes in holding Israeli leadership to account for the humanitarian crisis in Gaza. Earlier this week, a group of rabbis representing a range of religious denominations and political perspectives met with the mayor privately in City Hall. Many asked that he lower the temperature. Politicians have made similar calls for sensitivity.

“You can’t divorce the dramatic increase in violence targeted at the Jewish community from the political climate and the tone and tenor of the discourse around Jews and Israel,” said Micah Lasher, who won the Democratic primary in June to represent the congressional district that includes Central Synagogue, in an interview Saturday.

Left-leaning Jewish leaders praised the mayor for reaching out to the rabbis and emphasized the many factors driving anti-Jewish hate. “It’s an oversimplification to connect the dots to an attack like this because of things he has said about Netanyahu,” said Jamie Beran, the chief executive of Bend the Arc, a progressive Jewish group. “We’re seeing so much antisemitic rhetoric come from the right.”

It was not immediately clear on Saturday what prompted Mr. Montes to enter the synagogue during services Friday, or what he intended to do inside. There are no known ongoing threats to Central Synagogue, according to the mayor and the police.

Soon after charging into the building, according to the police and a video of the disruption posted online, Mr. Montes was grabbed by a security guard who tried to escort him down the temple aisle and out of the building.

Mr. Montes grew agitated, the video shows, punching the air with his arms and yelling into the temple’s interior. As he struggled, he hit a 63-year-old congregant in her face with his hand, cutting her lip, and spat at and head-butted a security guard, the police said. Mr. Montes also knocked over a set of candlesticks before a police sergeant who was providing security to the synagogue.

He was charged on Friday night with assault as a hate crime and criminal mischief as a hate crime, along with other charges, Police Commissioner Jessica Tisch said.

Though Mr. Montes’s mental state on Saturday remained unclear, a law enforcement official who was not authorized to speak publicly said that he had a history of mental health issues documented with the Police Department. Before Friday, Mr. Montes had also been arrested at least three times in New York City on a series of robbery charges.

A social media account that shared a name with Mr. Montes showed a handful of posts criticizing Mr. Mamdani and several more that mention Judaism or used Hebrew.

This isn’t the first time that Central Synagogue has been shaken by hate. Last year, a man posted threats targeting the synagogue as he drove across the country from Utah, before he was arrested at the Lincoln Tunnel on his way into New York. The community’s head rabbi said people continued to fill the sanctuary week after week and embrace the community’s commitment to keeping its doors open to all, with security offering protection.

“Ever since Oct. 7, our sanctuary has people filling the floor and into the balconies every single Friday night,” Rabbi Buchdahl said. “I’m moved to tears by the resilience and strength and courage, because I know it takes a lot of courage sometimes to do that, to just show up. Showing up is not a small thing. It’s its own act of defiance.”

Ms. Tisch, who is Jewish and said she grew up attending services at Central Synagogue, has spoken often about the growing number of attacks against Jews in the United States and abroad since Oct. 7. In response to some of those incidents, the city has at several points increased the presence of police officers at Jewish houses of worship and other cultural sites to bolster protections for its Jewish population.

It was not clear if any such deployment was in place at Central Synagogue on Friday, but the commissioner said the temple was receiving additional police resources after the disruption.

On Friday night, congregants continued singing, the rabbi at the front of the room edited her sermon to address the incident and members of the community exchanged hugs of relief and release.

“I certainly had a drink,” said Arlynn Greenbaum, a member of the community who witnessed the event. “We go on. Let’s keep living.”