Police say several officers were injured, but park-goers claim the heavy police presence instigated the crowd.
Thousands gathered in Washington Square Park on Sunday as the city celebrated its annual Pride March, but the party turned tense around 7 p.m.
Cell phone video shows hundreds of police officers in riot gear making their way to the park.
"The NYPD attacked queer people celebrating Pride," witness Ash Tifa said.
Some of the clashes between police and park-goers were captured on video.
"A group of NYPD officers attacked and grabbed and arrested people who were simply standing on the sidewalk," said Jay W. Walker, with the Queer Liberation March.
At least four people were arrested in the park Sunday evening with charges ranging from disorderly conduct to assaulting a police officer.
The NYPD says people threw bottles at police.
"They create provocative situations in hopes that they will create an aggressive response from protestors," Walker said.
Sunday's skirmish comes after weeks of contention around the park.
Residents have been complaining about disorderly party-goers destroying property and attracting violence at night.
The NYPD recently enacted and then lifted a 10 p.m. curfew.
"The NYPD's presence was entirely unnecessary and only served to escalate and cause violence in a crowd of peaceful, chill and joyful Pride attendees," witness Carli Rhoades said.
CBS2's Ali Bauman spoke exclusively with Chief of Department Rodney Harrison about Sunday's confrontation.
"Couple incidents where we asked people to move and, unfortunately, they got agitated. Had two assaults on a police officer, which was a concern," he said.
The chief admits officers used pepper spray on the crowd.
"It's currently under investigation and our Manhattan South investigation team will determine what there's gonna be a need for, if there will be any punitive actions that will come from it," Harrison said.
Bauman asked the chief how he plans to police the park without adding to these tensions going forward. He says the answer is communication between officers and park-goers.
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