Parents are upset and an investigation is underway by both law enforcement and Warren County Schools after authorities say three five-year-old girls were touched inappropriately by a nine-year-old boy on a school bus.

It happened a week ago Monday, but some parents say no one told them until three days after.

And now, the school admits that one of their principals made a mistake.

"You never expect something like that to happen to your kids," said a mother of one of the little girls.

It's what allegedly took place following a day at Oakland Elementary that came as a shock to the mother of one five-year-old student.

"My daughter was on her way home from school on the school bus and some inappropriate touching had happened that day," she said.

The Warren County Sheriff's Department says three girls were touched near their privates by a nine-year-old boy with "special needs," on their school bus last Monday afternoon.

"It's not his fault, nor is it his mother's fault," the parent said. "It is the school's fault for not telling us about it."

The mother says it wasn't until three days after the incident that she finally learned of what had happened -- but she was told by her daughter.

"My daughter has been seeing the counselor at school for a week about this, and I was never informed about it," the mother said.

She says her daughter told the bus driver about the incident, who then told Principal Mike Johnson.

But school officials say Johnson didn't immediately tell parents, nor the Board of Education.

"Not every day is perfect," said Joanie Hendricks, public relations coordinator for Warren County Schools.

Hendricks says Principal Johnson both handled and addressed the situation as he should have.

But neither Superintendent Tim Murley, nor the victim's family found out until Thursday, and the school says that is a problem.

"To my understanding, there was not communication made to the parents. And that's where the mistake lies here," Hendricks said.

Hendricks says Superintendent Murley has met with Principal Johnson to ensure a situation like this never happens again.

But parents who say they were kept in the dark on this issue want more to be done.

"To know that it was kept a secret by the one person you're supposed to trust when you're at school, it was an unbelievable thought," the mother of the five-year-old said.

We spoke with the nine-year-old's mother, who says her son has been removed from the bus and has also been placed in an in-school detention.

She says she was notified of the incident a day after it happened and she says that should've been the case for everyone involved.

No criminal charges are expected to be filed against the boy.