NEW YORK (CBSNewYork) — Police are looking for a man who threatened and attacked people on the Upper East Side. Three incidents were reported within 30 minutes.

A woman was targeted Monday morning on 85th Street near Park Avenue, and her attack was captured on surveillance video, CBS2’s Aundrea Cline-Thomas reported.

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The 21-year-old victim is seen on her cellphone at around 11 a.m. when a man walks up and punches her in the face. Inside the building, another man came to the victim’s aid. He asked not to be identified.

“She just stepped in, in shock. She was actually crying. I approached her and asked her what happened. She couldn’t talk at all,” the man said.

Police are searching for a man behind three apparently random attacks within 30 minutes yesterday on the Upper East Side. (Credit: NYPD)

What made the incident even more shocking was the fact that the attack seemingly came out of nowhere. It didn’t appear that any words were exchanged.

The victim works nearby. The suspect slugged her and kept on walking.

“As soon as she told me that I stepped out but there was nobody there,” the good Samaritan said.

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So he called police.

Authorities revealed that minutes earlier the same suspect brandished a knife and threatened a man just blocks away at 82nd and Park.

The suspect is also wanted for brandishing a knife and chasing down an eyewitness on East 87th and Third.

“It’s surprising because it’s usually a safe neighborhood around here. I’ve been here for four years and I’ve never heard anything like this,” the Samaritan said.

The suspect is believed to be approximately 25 years old, 5-foot-6, 115 pounds, with a thin build, dark complexion, short black hair and goatee. He was last seen wearing a black hooded sweatshirt, three-quarter length camouflage hooded jacket, blue jeans and black sneakers.

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Anyone with information about the crime spree is asked to call the NYPD’s Crime Stoppers hotline at 1-800-577-TIPS (8477) or 1-888-57-PISTA (74782) for Spanish. You can also submit a tip via the Crime Stoppers website, by tweeting @NYPDTips or by texting 274637.