At least 17 Jewish community centers in the eastern and midwestern US were targeted with bomb threats Monday, the latest in a series of incidents that has raised fears of anti-Semitism in the country.

Threats were called in to JCCs in Asheville, North Carolina; Birmingham, Alabama; York and Harrisburg, Pennsylvania; Tarrytown, Plainview and Staten Island, New York; Indianapolis, Indiana; Cherry Hill, New Jersey; Davie, Florida; Ann Arbor, Michigan; and Wilmington, Delaware.

Jewish day schools in Rockville, Maryland, and Fairfax, Virginia, both outside Washington, DC; and Davie, Florida, outside Miami, were also evacuated.

Parts of the Providence Road campus of the Shalom Park non-profit Jewish organization in Charlotte, North Carolina, were also partly evacuated, The Charlotte Observer reported; the Jewish Federation of South Jersey in Cherry Hill, New Jersey, was also cleared .

In total, at least 17 Jewish institutions were targeted.

Those inside the buildings were evacuated and law enforcement was called in to investigate the threats. All clears were given in a number of cases.

The director of the Birmingham JCC, which has been targeted three times in the past two months, told local media the threats were “very difficult, very challenging, very fearful.”

Several of the JCCs targeted were near Philadelphia, where a day earlier a Jewish cemetery was found vandalized, with some 100 headstones damaged or knocked over after a Jewish cemetery in St. Louis, Missouri, was targeted the previous week.

Paul Goldenberg, director of the Secure Community Network, told JTA shortly after reports of the bomb threats began coming in that his organization was working closely with the Department of Homeland Security and the FBI to identify the perpetrators and stop the threats. SCN is an affiliate of the Jewish Federations of North America that advises Jewish groups and institutions on security. SCN also is working closely with the Anti-Defamation League, Goldenberg said.

Calling the continued threats “disturbing,” he said they are “impacting the lives of our communities out there.”

Goldenberg also said the Jewish institutions are “behaving in an exemplary manner” in the wake of the threats.

“Our Jewish schools and our JCCs continue to train for this, continue to execute well-placed measures,” he said, going on to praise the staffs of U.S. Jewish institutions as “vigilant.”

No actual bombs have been found at any of the dozens of institutions that have received bomb threats in recent weeks.

“The goal of these people is to wear us down,” Goldenberg said. “But we are back in our schools, we are back in our JCCs.”

On Monday a week ago, 11 JCCs across the country received bomb threats from callers, the fourth such wave of threats in five weeks. In all, several dozen JCCs have received bomb threats, some multiple times.

Jewish groups and others have raised alarms over the bomb threats and cemetery attacks, pointing to an uptick in anti-Semitic incidents in the wake of the 2016 presidential election.

Earlier Monday, Israeli opposition leader Isaac Herzog urged Prime Minister Benjamin Netanyahu to establish an “emergency national program” to prepare for a “waves” of Jewish immigration following a series of anti-Semitic incidents in the United States and France.