A clarification to an earlier version of this story has been appended to the end of the article.

ALAMEDA — Graffiti described by school district officials as anti-Semitic was discovered at Edison Elementary School over the weekend, less than a month after parents gathered on the campus to talk about ways they can challenge messages that denigrate Jews and other groups.

The graffiti found Saturday referenced Adolf Hitler, according to Sean McPhetridge, the superintendent of the Alameda Unified School District.

Police are not classifying the incident as a hate crime, however, and said the message repeated dialogue that an actor said in the popular television show, “The Office.”

“It was a line said by the star of the series to one of his employees during season 6 episode 25,” Alameda police Lt. Hoshmand Durani said via e-mail. “It’s readily available on YouTube. Our case is closed and there’s no further police follow-up.”

The graffiti left at Edison follows racist tags being spray-painted at five locations at the school last November and a Jewish student at Alameda High School recently received a series of anti-Semitic text messages from a classmate.

“We cannot ignore these incidents if we are to ensure a safe and inclusive learning community for all students, staff, and families,” McPhetridge said in a letter Tuesday to parents and others in the district. “We cannot and will not condone any acts of hatred.”

Racist incidents also have recently occurred at Piedmont High School, where students allegedly formed a swastika during a dance and gave Nazi salutes in the hallways, and at Albany High School, where four students were suspended after an Instagram post surfaced reportedly showing a noose, a torch and a Ku Klux Klan member.

Some say the incidents are part of an uptick in racist and anti-Semitic violence and vandalism nationwide sparked by the aggressive rhetoric of President Donald Trump during last November’s presidential campaign, as well as his ongoing efforts to oust undocumented immigrants and restrict who may enter the country.

The most recent graffiti at Edison was reported about 9:30 a.m. Saturday, police said.

Susan Davis, a spokeswoman for the school district, said the writing was done with a marker and was on a ramp that leads to the school office. A teacher initially reported it to the principal. The writing was removed soon after it was discovered, Davis said.

McPhetridge said anti-Semitic actions and speech diminish everyone, regardless of their faith.

In response to the graffiti at Edison and other recent incidents, the district will update its literature lessons for kindergartners through fifth-graders over the summer to help students learn about all people, especially those who may be singled out due to race, religion or for other reasons, McPhetridge said.

The district also will roll out a new English Language Arts curriculum with a strong “social-emotional” learning component, he said.

“And when school begins again in August, we will reiterate the need for staff, students and families to report any incidents of bigotry, hate and bullying,” McPhetridge said.

After the racist graffiti was found at Edison in November last year, parents and others rallied at campuses across the Alameda school district to call for inclusion.

The discovery also prompted the May 31 meeting at Edison, at which Jacqueline Regev, an education director for the Anti-Defamation League, urged those gathered to actively support tolerance for all sides in America’s political debate, especially in the classroom.

Clarification: June 22, 2017

An earlier version of this story referred to graffiti referencing Adolf Hitler that was discovered at Edison Elementary School in Alameda over the weekend as anti-Semitic. While school district officials described the wording as anti-Semitic, Alameda police do not believe there is sufficient evidence to show that was the motivation behind the tag.