Police are trying to identify the person or people who slathered graffiti on the front of the Mercer County High School building and at least one school bus.
Mercer County Public Schools spokeswoman Becky Holt said Friday that officials notified Harrodsburg police, and that the district's school resource officer also is investigating.
The graffiti was discovered when personnel arrived at the high school early Thursday. Custodial staff "worked incredibly hard" to remove it, Holt said.
Initial news reports said the graffiti left overnight included racist slurs or images. Holt said it was "highly inappropriate."
"I'm not going to say it was racially charged; there were several inappropriate things," Holt said. "The whole thing was just very inappropriate and very disheartening.
"It's surprising that anyone would put that on our building because we don't have that kind of atmosphere here."
The high school has security cameras, but it isn't yet known whether recordings show the people involved, Holt said.
"Nothing has been discovered at this point," she said. "It's unclear whether it was one person or more. It could have been more, just because of how much was on the building and the time it was done to be there when students arrived at school.
"It's very distasteful," she said.
Friday was the last day of classes in the Mercer district.
"This is the time of year when we should be celebrating," Holt said. "It's the last day of school and kids are graduating. It's very unfortunate."