An Occupy Wall Street march through the financial district on Wednesday night ended at Zuccotti Park, where the police arrested at least four people, witnesses said.

The officers also told others that they had to leave the park.

Among those removed was a 56-year-old woman who said she was told that she was not permitted to sit in a folding chair inside the park. The woman, Marsha Spencer, from Hell’s Kitchen, said that she was using purple yarn to knit a covering for a water bottle, when she was surrounded by a contingent of police officers and private security guards working for Brookfield Properties, the park’s owner.

“They told me that I couldn’t have my chair in the park,” Ms. Spencer said later, by telephone. “I asked them to show me where that was in the rules.”

Ms. Spencer, who has become a familiar figure inside Zuccotti Park since she began knitting there last September, said the officers told her that they would discuss the rules with her after she left.

As she was getting up and gathering her things, Ms. Spencer said, a commander wearing a white shirt and black leather gloves grabbed her and began guiding her from the park.

A video shows Ms. Spencer, wearing an orange hat, trembling as a police captain with a nameplate reading Lombardo ushered her toward a sidewalk through a milling crowd of police officers and protesters, with some shouting objections.

Ms. Spencer said she lost several items, including a ball of yarn and her knitting needles. But she was particularly disturbed at being forced from the park.

“I was shaking so hard I couldn’t walk,” she said. “It really scared me.”

A man with a Mohawk haircut who can be seen on the video, apparently reaching for some of Ms. Spencer’s possessions as she was led from the park, was arrested a few moments later, witnesses said.

“It didn’t seem like he was doing anything wrong,” said Paul Moore, 25, from Ditmas Park, Brooklyn, adding that the man may have been pushed into a police line in the confusion. Some witnesses said that a second man, who can be seen in the video recording events with a mobile phone and wearing a hat with an American flag motif, was also arrested after Ms. Spencer was out of the park.

Because of zoning concessions granted to the developer of a nearby tower owned by Brookfield, Zuccotti Park is required to be open to the public 24 hours a day. Last fall, Brookfield adopted new rules for the park that included a ban on tents, sleeping bags and lying down. Those rules did not include sitting in a chair.

The police said that four men were arrested for blocking sidewalks and refusing to move. They were charged with offenses that included disorderly conduct, trespass, resisting arrest and obstructing governmental administration.

Brookfield did not respond to questions about the park’s rules.

In January, the National Lawyers Guild, the New York Civil Liberties Union and the Center for Constitutional Rights wrote a letter to the City of New York saying that rules that do not appear in any written form, like prohibiting musical instruments or food, had been used arbitrarily to keep some people from the park.

On Wednesday, witnesses said, police officers and security guards said at various points that backpacks were not permitted in the park and that people could not distribute food there.

James McGuinness, 55, from Bluefield, W.Va., said he was among a few people who were ladling plates of pasta out of a container when security guards and the police told them to stop.

“The cops came by and said you can’t serve food here,” Mr. McGuiness said, adding that the group moved to a nearby sidewalk.

The gathering in the park occurred after a crowd of more than 100, including some who had traveled from Philadelphia, marched from the Staten Island Ferry Terminal to Federal Hall, witnesses said.

Videotape shows parts of two arrests that took place near the western edge of the park and preceded Ms. Spencer’s removal. A man wearing a tricorn hat and carrying a snare drum can be seen in handcuffs, and the segments also show a photographer wearing a blue T-shirt being grabbed and arrested.