Cemetery officials said they were overrun with calls, emails and visits on Tuesday from distressed families. But callers also asked whether the vandalism at this 124-year-old cemetery might be another in a rash of anti-Semitic episodes occurring in recent weeks. On Tuesday, President Trump condemned the episodes, which some critics argued were an outgrowth of the vitriol of last year’s presidential campaign and Mr. Trump’s tone during it.
Since the start of the year, at least 53 Jewish community centers around the country have received bomb threats, according to the J.C.C. Association of North America. More than a dozen of the facilities, including centers in Albuquerque; Baltimore; Birmingham, Ala.; Milwaukee; and Wilmington, Del., have reported repeated threats. In addition, jarring graffiti of swastikas have been reported on some college campuses as well as the New York City subway.
“While we are relieved that all such threats have proven to be hoaxes and that not a single person was harmed, we are concerned about the anti-Semitism behind these threats, and the repetition of threats intended to interfere with day-to-day life,” said David Posner, the director of strategic performance for the North American J.C.C. group, which also said that a facility in Canada had been threatened.
Ron Glazer, 61, said the cemetery where his parents and grandparents were buried was widely known as a Jewish cemetery and had never, in his memory, been vandalized.
“You don’t expect this in a cemetery, and with everything that’s been going on, you cannot help but wonder and worry,” he said. “I can’t believe this is happening here and now, but it is. And people need to speak out on it.”
The law enforcement authorities, who have made no arrests in the Missouri case, said they had no indication that the vandalism was a hate crime, and no investigators have publicly suggested a link between this and the scores of other anti-Semitic episodes. Yet many of the families drawn to the cemetery on Tuesday said that they sensed an increasingly sinister mood behind the pattern of threats.
“We’ve never had this level of anti-Semitism — from different places on the ground, on your phone, literally over the phone — come at a time when hate groups and white supremacists, in particular, felt they had a champion in the highest office,” said Oren Segal, the director of the Anti-Defamation League’s Center on Extremism.
The Federal Bureau of Investigation and the Justice Department’s Civil Rights Division opened an inquiry into the bomb threats last month, and a spokeswoman for the F.B.I. said Tuesday that the bureau was “aware of the incident in University City.”
“If, in the course of the local investigation, information comes to light of a potential federal civil rights violation, the F.B.I. is prepared to investigate,” the spokeswoman, Rebecca Wu, said in an email.
The police in University City, with a population of about 35,000, said investigators were reviewing surveillance videos in the aftermath of the episode, which may have happened on the Jewish Sabbath. (The cemetery is closed on Saturdays.) Fences surround the cemetery, and the gates are locked at night.
Credit Nick Schnelle for The New York Times
Although most hate crimes in the United States are connected to biases involving race, ethnicity or ancestries, the federal authorities recorded 664 anti-Jewish incidents in 2015, the most recent year for which F.B.I. data is available. That was an increase of about 9 percent from the previous year, but the number of episodes remained far lower than in some other recent years, like 2010, for which federal officials reported 887 anti-Jewish incidents.
“Something has been released over a period of, I would say, a couple of years now,” Mr. Segal said. “Some of it is people literally feeling emboldened by the divisive rhetoric. Other parts of it, frankly, are the ability of people to harass and create fear with much more ease than any other time in human history.”
Jewish organizations have long been aware of security risks. Indeed, the first of 18 best security practices recommended by the Anti-Defamation League is to “make safety and security part of the culture of your institution, involving staff, leadership and constituents.” Another recommended practice is developing a bomb threat response plan.
“Security is part of the culture of the Jewish community in this country and, frankly, around the world,” Mr. Segal said. “You can be prepared and outraged at the same time, and concerned at the same time.”
Still, synagogues, not community centers and cemeteries, have historically been seen as the most threatened. Mark Potok, a senior fellow at the Southern Poverty Law Center, which also tracks anti-Semitic activity, said that he thought that the recent harassment of community centers was driven by the perception that they were so-called soft targets, especially in comparison to houses of worship.
“The kind of thing like the bomb threats strikes me as being trolling on steroids,” Mr. Potok said. “It’s not actually blowing up anything, but it’s causing an incredible amount of havoc, and it’s possible to do anonymously.”
Extremism researchers say that a small group of people could be behind the phone calls and that it is to soon to know whether the vandalism in Missouri is directly connected to the bomb threats.
But Mr. Potok cautioned that the desecration of the cemetery should be seen as alarming.
“My guess is it might be bored and extremely unpleasant teenagers, but it’s not pure happenstance that it’s a Jewish cemetery,” he said. “They may not be big-time, serious anti-Semites who deny the Holocaust and all the rest, but they might be little gangsters who are prodded on by the enormous amount of anti-Semitic propaganda.”
Here in Missouri, Gov. Eric Greitens announced on Tuesday that he would assist in cleanup at the cemetery on Wednesday afternoon.
Although the police cautioned against linking the University City vandalism to other crimes, the destruction here still resonated powerfully and broadly as a symbol of contemporary anti-Semitism.
On his television show on the Bravo network, Andy Cohen noted that he had relatives buried in the cemetery. Speaking during his broadcast, Mr. Cohen added, “I don’t have to have a personal connection, though, to know that this is not who we are as Americans, and this certainly should not be where we’re heading.”
The vandalism, blended with the broader wave of anti-Semitic activity, was demoralizing, Mr. Cohen said.
“This does not feel like a coincidence,” he said. “We cannot allow acts of hate against anyone to become normal.”
By late Tuesday, cemetery workers, some bearing maps and elaborate paper files, were conducting a meticulous search of every grave to try to figure out how many stones had been toppled and how many were seriously damaged. Some of the cemetery’s oldest gravestones were in the section that was vandalized. A monument company had arrived to assist in putting some stones that had simply been knocked down back up. Others, officials said, will require repair.
“We are working as fast as we can to get a complete list together because we know how much people need to know about their families,” Anita Feigenbaum, the cemetery’s executive director, said. “We’re going row by row, stone by stone. These families need to know.”