The victim, who did not want to be identified, was on her way home from school and says she tried to defend herself while on the bus.
On the back of the bus were 8-10 teenagers who were up to no good.
RELATED: 13-year-old suffers skull fracture when man attacks him
At first they were harassing senior citizens, and then they turned their attention on the 15-year-old.
"They started hitting me with Rice Krispies and Pop-Tarts," the victim said.
The 15-year-old then said they hit her with a rubber band, and it went right through her glasses.
When she spoke back at them, she felt a hard blow to her face - then another and another, leaving her bruised and bloodied in a brace in the hospital.
She says she does not know her attackers, but police said Friday they arrested two of them, a 13-year-old and a 14-year-old.
School officials say NYPD officers are monitoring students as they board their buses.
Officials also said, 'we are also exploring other actionable steps to ensure our students' safety on their way to and from school.'