The Jefferson Parish Sheriff’s Office said Thursday that it is investigating reports that a “sexual” incident occurred on a school bus last week involving three students from a public elementary school in Marrero.

A 13-year-old boy is the suspect, and two girls younger than 10 are the victims in the incident that happened on May 5 but wasn’t reported until Thursday morning, Col. John Fortunato said.

The three children are students at Estelle Elementary School, which serves pre-K through seventh grade.

During a phone interview Thursday evening, a woman identifying herself as the grandmother of one of the girls said she had been told that her 5-year-old granddaughter had been forced to give oral sex to a seventh-grade boy.

The woman posted a Facebook video Thursday asking that witnesses come forward and that parents at the school check whether their children were previously victimized.

The woman said she was alerted to the incident on the bus by the other girl’s mother.

The New Orleans Advocate is not releasing the women’s names to protect the identity of the two girls.

Fortunato said the Sheriff’s Office is investigating the matter “thoroughly” but had no other comment.

A statement released by Jefferson Parish Public School System spokeswoman Beth Branley said the driver of the First Student Inc. bus on which the incident reportedly took place “has been removed from the route and will no longer drive” for the district.

“We were made aware (Thursday) of (the) reported incident ... (and) took quick and decisive action, including reporting the reported incident to the Jefferson Parish Sheriff’s Office,” the statement said.

First Student Inc. management could not be reached for comment Thursday evening.

The school district’s statement added that a team of counselors would be available to meet with students at Estelle if needed on Friday. “The safety and well-being of our children is of utmost importance,” the statement said.