Upper Makefield Township police said Sunday that a campaign sign for Democratic gubernatorial candidate Josh Shapiro was placed without permission on someone’s property, and while trying to remove it the resident found that razor blades had been “placed around the perimeter of the sign.”

“Obviously, this was designed to inflict punishment on anyone who attempted to remove the sign,” police said in a social media post.

Police said they inspected all campaign signs and found razor blades placed around the perimeter of signs for two other Democratic candidates, John Fetterman and Ashley Ehasz. Fetterman is running for U.S. Senate and Ehasz for U.S. House.

Police said their investigation continues and warned residents to exercise caution in removing signs placed on their property without permission, and to call them if “any implements” have been installed on the signs.