Authorities are investigating after threatening graffiti was found in a bathroom at Lincoln Park High School on the North Side.

Officials at the school, located at 2001 N. Orchard St., were “made aware of a potential threat to the school” on Wednesday, according to an email sent to parents.

A LPHS parent said graffiti referencing a shooting on Dec. 14 was found in a bathroom.

It was reported to police about 9 a.m., Chicago police said.

“We take all threats very seriously, and we immediately contacted the Chicago Police Department and CPS Office of Safety and Security,” officials wrote in the email.

While the threat is being investigated, the school will use metal detectors and X-ray machines to scan “all students and their personal items such as book bags,” officials wrote.

Police did not provide further details about the threat but said they will be working with CPS to “implement additional security precautions” as detectives investigate.

Chicago Public Schools officials did not immediately respond to a request for comment.