Protesters fill the streets in New York to support Palestinians in Gaza.

Crowds of pro-Palestinian demonstrators packed the streets of Brooklyn on Saturday as they called on the U.S. government to stop sending aide to Israel.

The march was organized by the Palestinian-led community group Within Our Lifetime, and participants stretched for several blocks as they traveled from the Brooklyn Museum to the Brooklyn Bridge, chanting “Free, free Palestine!”

The demonstration was the latest in a string of protests around New York City since Hamas attacked Israel on Oct. 7. Saturday’s march took place a day after Israeli forces began what Prime Minister Benjamin Netanyahu of Israel called “the second stage of the war.”

Waving a Palestinian flag as she marched, Alaa Essafi said that after Israel’s escalated attacks, it felt especially important that she travel from her home in New Jersey to support her “brothers and sisters in Palestine.”

“Together we will send a message,” Ms. Essafi, 21, said.

The museum has a large outdoor plaza, and it has been the site of several large-scale gatherings, including a Black Lives Matter demonstration in 2020 that drew more than 15,000 people.

Standing outside the museum, Hany Barakat, 34, said he had family in Gaza and that some had been killed during recent airstrikes.

“It has to stop.” said Mr. Barakat, who is Egyptian and lives in New Jersey.

The protest prompted the police to shut down several blocks of the Eastern Parkway. Helicopters and a drone hovered above the crowd.

The crowd waved banners and held signs that bore messages including, “We demand a free Palestine” and “Let Gaza Live.” At the Brooklyn Bridge, a few people scaled a metal support structure and unfurled Palestinian flags, prompting protesters to erupt into chants of, “Gaza! Gaza! Gaza!”

The demonstration began to thin as it crossed into Manhattan and daylight faded. Just before 7 p.m., as the crowd streamed through SoHo, the Muslim call to prayer echoed through the streets and event organizers instructed everyone to stop marching to allow time to pray.

The final destination was Union Square, where hundreds of protesters stopped to beat drums. Some carried signs that read, “Support Palestinian resistance,” while others climbed the square’s iconic George Washington statue.

Liset Cruz and Michael D. Regan contributed to this story.