WILDWOOD, N.J. (CBSNewYork) — A violent arrest on a New Jersey beach was caught on camera.

Police in Wildwood say they’ve launched an investigation after a video surfaced showing one of their officers punching a young woman on Saturday, CBS2’s Hazel Sanchez reported Sunday night.

The woman was confronted about underage drinking, but things got heated quickly after officers pinned the 20-year-old to the ground, one punching her in the head in front of a shocked crowd.

Lexy Hewitt was sitting nearby and recorded the take-down with her phone. The video has since gone viral.

“She started screaming initially. It was almost like blood-curdling,” Hewitt said. “The officers were on top of her on the ground and that’s when I just decided — there’s so much going on everywhere — why not, just in case [record the incident].”

Wildwood police identified the woman in the video as Emily Weinman of Philadelphia. She can be heard protesting her arrest and how officers were handling her.

“You’re not allowed to hit and choke me like that!” Weinman says.

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Weinman posted on Facebook that she was at the beach with her 18-month-old daughter, her child’s father and a friend when police approached her and asked her age.

Weinman wrote, “I had alcohol,” but that “I told them I wasn’t drinking and the alcohol was clearly closed.” Later, she added, “…we got Breathalyzed, and it came back negative.”

She admitted to repeatedly refusing the officers’ requests to give them her name, and said when they approached to handcuff her she tripped and cops tackled her. Witnesses can be heard pleading with her to stop resisting the officers.

Weinman conceded she should have given police her name, writing, “I was partly wrong in a way. But I was scared.”

Wildwood’s police chief called the video “alarming.” The officers involved have been placed on administrative duty pending the results of an internal affairs investigation. The officer seen punching Weinman is wearing a white Class II police officer patch on his sleeve, meaning he is fully trained but only works during the summer season, not full time.

Weinman faces multiple charges, including aggravated assault on a police officer, resisting arrest, disorderly conduct, obstruction and minor in possession of alcohol.