Kern County sheriff's deputies are investigating a report of an assault against a 13-year-old Fruitvale Junior High School student on a school bus Tuesday.

Sheriff's spokesman Ray Pruitt said the girl reported being assaulted by two or three male students while on the bus after school. Pruitt said that so far investigators have not determined whether sexual battery -- or any crime -- occurred.

The incident was reported to deputies Wednesday by the school's principal, Pruitt said. He said he could not release details on what the girl specifically said happened.

Dr. Mary Westendorf, superintendent of Fruitvale School District, confirmed there was an investigation but referred all questions to the sheriff's department.

The investigation is ongoing.