"Morale is as high as it can be," Guy Steward, 18, told the amNew York newspaper.
The Occupy Wall Street movement's ranks have grown, he said, despite what he called "mass police brutality" Saturday when about 80 people were arrested as they marched from a park in the financial district, where many had been encamped for more than a week, north toward about 3 miles to Union Square, a large public square off Broadway.
The National Lawyer's Guild, providing legal assistance to the protesters, said more than half of those arrested were released Sunday and the rest would likely be freed by Monday.
Witnesses told the New York Daily News they saw three stunned women collapse on the ground screaming after they were sprayed in the face with Mace, or pepper spray.
Videos posted on YouTube by USLaw.com and by people identifying themselves with the protest show uniformed police officers corralling the women using orange nets -- a tactic known as "kettling" -- then show two police supervisors making a beeline for the women, with at least one spraying the women before turning and quickly walking away.
After the spraying, two women can be seen dropping to the ground, screaming in apparent pain, a United Press International review of the videos indicated.
New York Police Department chief spokesman Paul Browne told The New York Times police had used the pepper spray appropriately."
Another video shows an officer wearing a white shirt -- indicating a rank of lieutenant or above -- kneeling on the back of the neck of young man pinned to the ground as he handcuffed him, the UPI review indicated.
A woman off camera says: "He can't breathe, officer. Please get off his neck. He's just a kid, officer."
Police did not provide the officer's identity and had no immediate further comment.
"Not the image or reality the U.S. wants, at home or abroad," Anne-Marie Slaughter, director of policy planning at the U.S. State Department from 2009 to February, said on Twitter.
The protesters -- promoted by a number of groups including AdbustersMedia Foundation, a Canadian advocacy group, and local groups called the General Assembly and the 99 Percent -- vowed to remain in Zuccotti Park near the World Trade Center site and to continue protesting for weeks or even months.
The 99 Percent group says its members "will no longer tolerate the greed and corruption of the 1 percent."
The protests, which started Sept. 17, are inspired by demonstrations in Egypt and Spain and could continue for weeks or even months, organizers say.