State police are investigating an assault on a 14-year-old girl on board a school bus.

Three teenage boys were charged in the alleged attack, which police said happened Wednesday afternoon at the Learning Academy in Alsace Township, Berks County.

Officials can release only limited information to the public because the case involves children 17-years-old and younger.

What state police did say is that the girl was walking down the aisle of a school bus that was parked in front of the building when she was pushed on to a seat. Two boys then pulled her legs apart while a third boy groped her above her shorts, investigators said.

"I'm sure it was very traumatic. She's a young person, too," said Tpr. Dave Beohm, a public information officer for the state police. "I don't know anybody, whether you're a young person or a 40-year-old woman, is prepared to deal with something like that."

The girl turned to the state police resource officer who is stationed at the school, said Beohm.

"The kids that go to school are kids that have been kicked out of the school," said Beohm.

Police said they are needed regularly at the school, but they said this case is really unusual.

"I know initially the boys weren't forthright with what happened," said Beohm.

Investigators said they are looking at surveillance video that was recorded inside the school bus.

"And if all the three boys say, 'She's crazy. We don't know what's she's talking about.' Well, that's her best witness, the camera right there and the footage," said Beohm.

The three students have been charged in juvenile court with a list of offenses.

"Indecent assault, conspiracy to commit indecent assault, harassment, and unauthorized boarding of a bus," said Beohm, who noted that the charged students could get probation if they have no prior offenses.

Beohm said the school also typically takes action by suspending students. The school did not have anyone available for comment on Thursday.