An aide in the Prince George’s County school system has been accused of molesting at least four students on a school bus.

A spokeswoman for county police said the incident allegedly occurred May 24. It was referred to Child Protective Services and then, on June 20, to police, said Cpl. Nicole Hubbard, the spokeswoman.

She said that the matter is under investigation and that she had no additional information.

It was not clear why the information did not become public sooner.

There was no indication that anyone had been charged in connection with the allegations.

A school system spokeswoman said a bus aide and a supervisor had been placed on administrative leave.

The spokeswoman said the alleged incident involved children from James Ryder Randall Elementary School.

Earlier this year, a school-system volunteer was indicted on 270 counts of child pornography involving at least 23 victims.

The county Board of Education has adopted new policies aimed at safeguarding children.