“This will not be a Seder as usual. These are not usual times,” Morgan Bassichis, a member of the progressive group Jewish Voice for Peace, said to attendees.

After a series of speakers addressed the rally, a large portion of the crowd moved into the street between the north edge of Prospect Park and the Soldiers’ and Sailors’ Memorial Arch, blocking the flow of traffic and prompting drivers to lean on their horns. Police officers who had been monitoring the event warned the demonstrators that they would be arrested if they did not move; when they stayed put, officers wielding zip-tie handcuffs moved in and began making arrests. In the frenzy, it was unclear exactly how many were arrested before the crowd dispersed. But it appeared that at least 100 protesters, some wearing reflective vests over black T-shirts that read “Jews Say Cease-Fire Now,” were led away in pairs.

The protest, organized by pro-Palestinian Jewish groups, marked what has been a distinctly different Passover celebration for Jewish people in New York City and beyond, as college campuses and family dinner tables feel the ripple effects of the Israel-Hamas war.

Stefanie Fox, executive director of Jewish Voice for Peace, said the protest was held during Passover in order to send a message to Mr. Schumer as the Senate moved toward a final vote on aid to Israel, Ukraine and Taiwan. Roughly $9 billion of that $95 billion package is dedicated to “worldwide humanitarian aid,” including for civilians in Gaza. (The package later passed in a 79-to-18 vote.)

“Everything in our tradition compels us to bring everything we have to stopping these historic atrocities being done in our names and with our tax dollars,” Ms. Fox said in an interview on Monday.

Mr. Schumer, the highest-ranking Jewish elected official in the United States, recently called for elections to replace Benjamin Netanyahu, the Israeli prime minister, once the war winds down. His rebuke of the Jewish state’s leader last month — in a speech in which he also spoke of his love for the state of Israel and his horror at the Hamas attacks of Oct. 7 — exposed the widening gap between Israel and the United States, its most important ally, analysts said.

“Senator Schumer just very recently spoke very harshly about Prime Minister Netanyahu on the Senate floor,” Beth Miller, the political director for Jewish Voice for Peace, said at the protest on Tuesday. “For him to do that with one hand, and then on the other hand reward Prime Minister Netanyahu by pushing forward this military funding package, shows that he is not serious about actually shifting U.S. policy to leverage change.”

One attendee, Calvin Harrison, 29, a community organizer who lives in Manhattan, said he was at Grand Army Plaza “because I’m a Jew and I was raised to believe that Judaism is about justice.”

“Passover is a celebration of liberation for the future,” he went on. “We can’t celebrate liberation for ourselves while we’re oppressing Palestinians.”