A 70-year-old Woodbury man was charged Thursday with sexually touching at least six girls, ages 3 to 5, who ride a bus to school in Woodbury.

The defendant, Harvey Theodore Kneifl, is a bus assistant on a route traveled by pre-K children, many of them with special needs, according to a criminal complaint filed in Washington County District Court.

Kneifl is charged with six counts of second-degree sexual assault. He was booked into the Washington County jail on Wednesday.

Police are investigating the possibility of more victims on the bus, where Kneifl’s job was to help children on and off and to buckle their seat belts, said spokeswoman Michelle Okada.

According to the complaint, a review of bus videos showed Kneifl touching girls “in a sexual manner over their clothing.” He told officers that “he likes to tickle, poke and hug the children, that he puts his hands on the girls’ thighs rubbing them.”

The suspect denied touching their genital areas, but claimed “he makes the girls feel good because ‘they come from a hard life and likely do not get any sort of affection at home,’ ” according to the complaint.

In addition, Kneifl “believes he becomes closer to the children than their parents, and he likes sitting by the girls on this bus because they are ‘more fun.’ ”

Officials in the South Washington County School District placed the employee on administrative leave when they learned of the police investigation, the district said in a statement. He was hired in July 2012, a district spokeswoman said.

Woodbury police learned of the allegations Saturday when parents of a preschool student reported their daughter told them she had been inappropriately touched the previous morning on the way to school, Okada said.

Officers contacted the school district’s transportation division on Monday, asking for bus videos, rosters and contact information for students on the suspect’s bus route and any other routes he has worked, Okada said.

All parents on the route are being contacted, “whether we believe their child was a victim or not,” she said.

The district confirmed to police that a background check had been completed before Kneifl was hired, Okada said, and he didn’t appear to have prior convictions.

Superintendent Keith Jacoby notified district parents on Thursday.

“The intent of this letter is to inform you of a developing situation, one that we take seriously,” Jacoby wrote. “It is not intended to communicate that there is an ongoing risk to any student or employee.”

The district declined to name the school the girls are attending.

County Attorney Pete Orput said in a statement: “What this defendant is alleged to have done is totally abhorrent to society. The case will be prosecuted with that standard in mind.”

Anyone with information on the case should call Woodbury police at 651-714-3600.

Also Thursday, charges were filed in Ramsey County against a former bus driver for allegedly touching a 4-year-old boy inappropriately in St. Paul in the summer of 2015. Charles E. Glover, 53, of Eagan, faces one count of second-degree criminal sexual conduct for allegedly pulling down the boy’s shorts and touching him after stopping the bus in Mounds Park.

Glover was charged in February 2016, but that case was dismissed because GPS data from the bus didn’t register a stop at the park. According to the latest criminal complaint, however, police analyzed the GPS data and found that on the day Glover was driving the boy, the bus took 149 seconds to travel a distance that should have taken 60 seconds — and on a road with no stoplights and one stop sign.

Glover was a driver for Twin City Transportation, which has provided special needs transportation services since 1989.

Staff writer Chao Xiong contributed to this story.