CBS (CHICAGO)–A disturbing discovery was made Wednesday at a Chicago park, where a woman found a swastika sticker with a razor blade tucked underneath.

Several more stickers and six razor blades were inside a brown paper bag that police later found at Kilbourn Park, at Addison and Kilbourn on Chicago’s northwest side.

Parent Laura Singer saw a photo of the racist sticker posted on social media site Nextdoor and shared it with CBS 2 Chicago. She said she was thankful someone noticed it and said something.

“At a park where kids are playing–people are scratching things off the sign all the time–I wouldn’t have thought there would be a razor blade there,” Singer said. “It wasn’t just a prank–it seems like someone put some real thought into spreading messages of hate throughout our park and maybe they were going to other parks.”

The person who found the sticker removed it from the park sign it was stuck to, police said.

“I hope we can work together as a community to let people know these racist thoughts are not ok in our neighborhood,” Singer said.