Police are asking for help tracking down a man who punched a woman and put her in a chokehold during a violent robbery over the weekend in Manhattan.

According to the NYPD, the incident took place at 2:20 a.m. on Saturday, May 29, near First Avenue and East 18th Street: "The suspect approached the 30-year-old female victim from behind, placed her in a chokehold and dragged her to the floor. When the victim tried to fight back, the suspect punched her in the face numerous times rendering her unconscious. When the victim regained consciousness the suspect was gone and she realized her cell phone was missing and her underwear had been lowered to her knees."

The victim was taken to Beth Israel Hospital for medical aid and evaluation.

Investigators released surveillance video of the suspect, describing him as about 150 pounds, 5'7" to 5'10" and 25 years old, with a beard. He was last seen wearing a black T-shirt, dark colored pants and a yellow metal chain around his neck.

Anyone with information in regards to this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782). The public can also submit their tips by logging onto the Crime stoppers website at WWW.NYPDCRIMESTOPPERS.COM or by texting their tips to 274637 (CRIMES) then enter TIP577. All calls are strictly confidential.