Palo Alto police are investigating graffiti at Ellen Fletcher Middle School as a hate crime after someone wrote "KKK" in two boys bathrooms on campus this week.

Administrative staff reported the vandalism to police on the afternoon of Wednesday, May 11, according to a police press release. The middle school is located at 655 Arastradero Road.

School staff had removed the graffiti by the time police arrived, but investigators determined that the graffiti had appeared in one restroom on Tuesday, May 10, and in a second on Wednesday, May 11, police said.

In the first bathroom, "KKK" was written on a stall and in the second on a toilet paper dispenser and walls, police said. Both times a pen or marker was used and investigators believe the two incidents were committed by the same person.

"Officers are actively investigating the case and working collaboratively with the school administration," the press release said.

In January, Palo Alto police announced they were investigating the vandalism of an outdoor sign at El Carmelo Elementary School as a hate crime. The sign had been defaced with "a racial epithet directed at Black people" and a cartoon image depicting two nonwhite children was crossed out, police said at the time.

No suspects have been identified and no arrests have been made in connection to the El Carmelo incident and investigators do not have any evidence connecting it to the graffiti at Fletcher, police said this week. Both cases remain open.

Anyone with information is asked to call the police department's 24-hour dispatch center at 650-329-2413. Anonymous tips can be emailed to paloalto@tipnow.org or sent via call or text to 650-383-8984.