Police in Maryland are investigating an incident involving a swastika at a suburban high school, the most recent in a string of hate-based vandalism acts. (J. Lawler Duggan for The Washington Post)

Montgomery County police and school officials are investigating an incident involving a swastika drawn on the wall of a high school boys’ restroom, the most recent in a string of hate-based vandalism acts in the suburban Maryland county.

The swastika was discovered Tuesday at Quince Orchard High School in Gaithersburg by a visitor to the campus, said Sgt. Rebecca Innocenti of the Montgomery County Police Department. The symbol was written in pen on a tile, she said.

“Detectives are working to determine when it may have been written,” she said.

The incident is the second at Quince Orchard since October, when a caustic substance was used on the football field to create the image of a swastika, according to Montgomery County police. An investigation is still underway, police said.

“This type of behavior will not be tolerated, and those found responsible will be subject to disciplinary actions aligned with the Student Code of Conduct,” principal Carole Working wrote in a letter home to families about Tuesday’s incident.

The vandalism follows other hate-based acts in the area, part of a surge of such incidents that has sparked concern from school officials, community members and parents. Police could not say whether any are related. They include:

●On Oct. 30, swastikas were found spray-painted on sidewalks, a telephone pole and a school banner outside Burning Tree Elementary School in Bethesda. The case is still under investigation.

●On Nov. 10, two students at Winston Churchill High School in Potomac taped a “whites only” sign on a boys’ restroom door, according to police. The students, identified through video surveillance, told authorities they found the sign outside the school and hung it up to see how others would react. No charges have been filed, but school officials say they have taken disciplinary action.

●On Nov. 11, numerous images of a swastika were found inside the boys’ bathroom at Westland Middle School in Bethesda, in the second such incident at the school during a two-week period. Suspects have not been identified.

●On Nov. 14, administrators at Sligo Creek Elementary School in Silver Spring, apparently alerted by parents, said they learned of a racial slur that was written in a boys’ restroom several days earlier. A mother posted on a parents’ email group that her son was among those who discovered the graffiti and that it read: “Kill Kill Kill Blacks.” Police say they found evidence of vandalism but not of a hate crime, with the words appearing to be “Kill Kill B.”

Montgomery County Schools Superintendent Jack Smith has called the trend “disturbing and unacceptable,” pointing out that such acts violate school policy and the law. “Most importantly, it is simply wrong,” he said in a video-recorded statement. Students who commit such offenses will be subject to disciplinary action, he said.

“Our schools must continue to be safe places for students to learn,” he said.

Ron Halber, executive director of the Jewish Community Relations Council of Greater Washington, attributed the uptick in incidents to a bitter presidential campaign that empowered people with hateful views. “They’ve lost their shame,” he said.

In school, Halber said, some offenders might be immature or rebelling and not realize the severity of their actions, while others might be driven by racist or anti-Semitic beliefs. Strong punishment could help address cases involving hate-based views, providing a deterrent to future activities, including a potential for hate-inspired violence, he said.

“You have to nip this in the bud,” he said.

The vandalism in Montgomery County comes as the Southern Poverty Law Center released a report this week documenting nearly 900 hate-based incidents in the 10 days after Donald Trump was elected president.

Trump’s transition team released a statement Tuesday saying that Trump denounces racism of any kind and vows to be a leader for every American.