Two high school students are under arrest and two others are on the run following a brutal attack Wednesday.
The attack took place around 1 p.m. inside a bathroom at John Bartram High School in southwest Philadelphia.
Police say 19-year-old Anthony Williams and three minors - all Bartram students- attacked a 9th grade student, stealing $50, his backpack and his cell phone.
"These guys came in the bathroom, they locked the door and they started to sucker punch him,"said Vofee Jabeth, the victim's uncle.
The attackers kicked his nephew while he was on the floor, Jabeth said, before he was able to escape.
Police arrested Williams and one of the three minors and charged them with aggravated assault and robbery. Williams was charged as an adult.
Another relative informed NBC10 that the 17-year-old victim, who immigrated from Liberia with his family less than a year ago, was treated for his injuries at the Children's Hospital of Philadelphia.
Officials say it is unclear why the student was targeted and Jabeth says his nephew did not even know the students who assaulted and robbed him.
"This is definitely what we consider a serious incident," said Fernando Gallard of the Philadelphia School District. "And the kind of incident we are taking immediate action, working with Philadelphia police."
Investigators say they know who the other two attackers are and are still searching for them.