Someone called police about a big, unruly group near the park just before 10 p.m. Friday. When cops arrived, they found the 15-year-old victim, bloodied and beaten, reports NJ.com.
The girl told authorities she and her cousin had been walking through the park when the group attacked her and stole her cell phone.
The victim's mother told police that she managed to get her daughter's cell phone back from one of the girls in the mob.
No further details were immediately available.