More than 500 people associated with the Occupy Wall Street movement gathered in Zuccotti Park on Saturday and, in a return to scenes from earlier in the year, the evening began with the sound of drumming and calls of the now familiar slogan, “We are the 99 percent” — and it ended with torn-down barricades and a scuffle with police officers.

Just after 10:30 p.m. on New Year’s Eve, officers carried a person out of the park, prompting protesters to follow behind them, shouting “Shame!” The reason the person was escorted away was unclear.

About 20 minutes later, a group of protesters grabbed some of the metal barricades that surround the park and began piling them inside. As they gripped the barricades, police officers took hold as well, and a shoving match began, the silver bars trapped in between. At least one police officer fired an arch of pepper spray into the crowd behind those barricades.

Moments later, at least a dozen police officers charged into the park, plowing directly into a crowd of people, some of whom were trying to flee, pushing and shoving. One man was thrown down and pinned to the ground by several officers.

In the park, some protesters shouted “Peaceful!” and “Nonviolent!”

As the scuffle subsided, a group of police officers gathered on Cedar Street.

The evening began more diplomatically.

About 100 people arrived at the park at about 7 p.m., according to witnesses, and someone put up what was described as a small multicolored tent, about two feet tall, made for a child. Two young girls, who were at the park with their mother, began playing inside.

Though the New York City Police Department had officers fanned out throughout the city for the holiday, there were police officers lined up across the street from Zuccotti Park, at the ready alongside private security guards. They stepped in.

Police officers and security guards, who stood at the ready across the street, told protesters to remove the tent, saying it violated rules issued by the park’s owner, Brookfield Properties. Meanwhile, an officer and a guard blocked other protesters, and at least one reporter, from entering the park. Some people disregarded their instructions and squeezed through the spaces between metal barricades along other parts of the perimeter.

According to Brendan Burke, an organizer with the Occupy movement, police and security officers said that if the tent was taken down, people would be permitted to enter. So shortly after 8 p.m., demonstrators dismantled the brightly colored tent and handed it over to security guards. The guards stepped aside, and protesters were allowed in, after their bags were searched.

In the six weeks since officers cleared the park in an overnight raid, a spot in its northeast corner has been cordoned off with bright yellow tape. That corner, with its high granite ledge, is where general assembly meetings were usually held. On Saturday night, the tape was down and the meeting reopened.

At one point, a man stood on the ledge and was ordered down by a security guard.

“You’re fighting a losing battle,” the man answered. “Give me one good reason why I should get down.

As midnight approached, the hundreds in Zuccotti Park shouted “Whose year? Our year!”

Just before 1:30 a.m., security guards and police officers entered the park, where only about 150 people remained. A line of officers pushed protesters from the park and led about five people out in handcuffs. One officer used two hands to repeatedly shove backwards a credentialed news photographer who was preparing to document an arrest.

A police commander announced through a megaphone that the park, which is normally open 24 hours a day, was closed until 9 a.m., but did not provide a reason. A few moments later, officers told the crowd that had just been moved from the park that the sidewalks surrounding Zuccotti Park were also closed, and directed people across Broadway.

Just before the park was cleared, about 200 protesters marched north through SoHo and into the East Village. At 13th Street and 2nd Avenue, officers surrounded dozens of protesters walking on the sidewalk around 3:00 a.m. and began arresting some of them.

“We were trying to go to Tompkins Square Park,” Isham Christie, who was on the march, said. “The police blocked us and we doubled back and they blocked us again.”

Mr. Christie said that about 50 people were eventually surrounded by officers on a stretch of sidewalk on Second Avenue. “They arrested most of them,” he said.