Tensions rose in Union Park late Thursday night during the final protest march outside the Democratic National Convention in Chicago. and in the final moments before Vice President Kamala Harris took the stage at the United Center a few blocks away.

After an earlier parade in the streets near the arena, it returned to West Side Park, Hundreds of police officers in Chicago began preventing a protest march against the Gaza war from continuing. The demonstrators said they would continue marching until Harris took the stage.

Many members of the crowd remained under the tracks on Lake Street at around 9 p.m., standing shoulder to shoulder, beating drums and chanting “Gaza! Gaza!”

Negotiations between a police liaison for the group and Police Commissioner Larry Snelling came to nothing, and organizers began urging the crowd to continue demonstrating in the coming weeks—a sign that the crowd would soon disperse.

“Please organize protests when you go home” they said. “To win, we must build an organization.”

Still, police remained vigilant as the Democratic presidential candidate delivered the biggest speech of her political career. A sit-in that began on Ashland Avenue, south of Lake, quickly grew to 60 participants.

The moment seemed to jeopardize a week that could have ended with mostly peaceful protests and only 72 arrests. Whatever the case, it will be a moment that will long be remembered in a city with a long history of political gatherings and activism.

“We learned here that preparation is everything,” Snelling told reporters earlier in the day. “To be successful, you need two things: opportunity and preparation. We had the opportunity to respond to the Democratic National Convention, and we were prepared.”

Hatem Abudayyeh, a local Palestinian activist and organizer of many of this week’s marches, called the week “incredibly successful” in which thousands took to the streets to demand that the ruling Democrats end US aid to Israel.

They also warned that Harris would lose the November election if she did not change course on the issue.

The protesters were determined to end the week with a strong result, creating a palpable contrast between the party celebrating Harris at the United Center and a group a few blocks away chanting genocide slogans and trying to get the attention of Democrats.

The group gathered in Union Park before starting a march down Washington Boulevard. Turnout appeared to be the same as previous marches on Monday and Wednesday, although the final crowd seemed denser, with people marching shoulder-to-shoulder in the street.

A member of the U.S. contingent “Out of the Philippines,” who did not want to give his last name for fear of reprisals, chanted along with the rest of the group as they arrived at the rally on Thursday: “No ground troops, no bombs in the air, USA out of every corner.”

In the sea of ​​Palestinian flags and signs condemning the killings in Gaza, some people also protested other causes. Signs read, for example, “Only struggle has won women’s rights,” referring to the rollback of abortion rights in many states across the country, and “Corporations are not people,” denouncing the U.S. Supreme Court’s 2010 ruling in the Citizens United case that allowed corporations to spend unlimited funds on elections.

But one theme emerged: a particular anger at Harris, who received thunderous applause as she took the stage at the United Center.

In the streets nearby they chanted: “Killer Kamala, you will see, Palestine will be free!”