Jewish Community Centers were shaken by another wave of bomb threats, forcing evacuations in 10 states Monday.

Eleven Jewish Community Centers received threatening calls Monday, said Marla Cohen, communications manager for JCCA, the Jewish Community Center Association.

Law enforcement officials were investigating the threats and, as of late Monday, centers were being reopened after explosive devices were not found.

For some of these organizations, it was not the first threat made in recent weeks. There have now been at least 67 incidents at 56 Jewish Community Centers in 27 states and one Canadian province since the start of 2017, Cohen told The Huffington Post.

Monday’s incidents are part a sharp rise in threats made against JCCs since January as well as a rise in anti-Semitism around the nation since Donald Trump began his presidential campaign, which was frequently criticized for winking at white nationalists and not forcefully condemning hate speech and extremism. Though hard numbers on previous threats against JCCs weren’t immediately available, several community centers and advocacy organizations characterized this year’s string of incidents as unprecedented.

“It is an intense climate right now between the spike in hate incidents post-election and the series of bomb threats targeting the Jewish community over the past couple weeks,” Elise Jarvis, spokeswoman for the Anti-Defamation League, told HuffPost previously. “The frequency and scale of this is at a level right now that’s higher than we’ve seen in a long time.”

Paul Goldenberg, director of the Secure Community Network, said there is “no denying that there has been a remarkable uptick in anti-Semitic hate incidents in the last 60 days.” The Network, which advises Jewish groups on security matters, is an affiliate of the Jewish Federations of North America and the Conference of Presidents of Major American Jewish Organizations.

The far-right has become emboldened under Trump, and while the number of Americans who directly support hardened hate groups remains far lower than in earlier decades, the number of hate groups in America is rising, according to a recent report from the Southern Poverty Law Center, which tracks hate and extremism around the nation.

Heidi Beirich, director of the Intelligence Project at SPLC, said that this series of bomb threats since the new year is “unprecedented.”

“I’ve been working at SPLC since 1999. I’ve never seen a string of attacks like this that are targeting the same kind of institution in the same kind of way. This is new,” Beirich said.

She added that it remains unclear who is making these threats, if it’s one person or more, but it has rattled communities around the U.S.

“This threatens an entire community. It’s very scary,” Beirich said. “You’re terrorizing whole families and children. There are usually day care centers that serve an entire population in the area. These threats can make it impossible for those communities to function normally.”

Anti-Semitic hate crimes comprise the largest portion of religiously motivated attacks in the United States. But Trump has yet to address the issue. In news conferences last week, the president had multiple opportunities to address concerns over rising anti-Semitism, but each time he either downplayed or denied the rise. When a Jewish reporter asked Trump explicitly about the recent spike in bomb threats against JCCs, Trump cut him off, told him to sit down and told the reporter his question wasn’t fair and claimed to be the “least anti-Semitic person that you’ve ever seen in your entire life.”

Deputy White House Press Secretary Lindsay Walters didn’t specifically address anti-Semitism, but did say in response to the latest bomb threats Monday, “Hatred and hate-motivated violence of any kind have no place in a country founded on the promise of individual freedom,” adding Trump has “made it abundantly clear that these actions are unacceptable.”

The Anti-Defamation League said it was “deeply disturbed” by the latest wave of bomb threats this week and issued bomb threat guidance for all Jewish institutions.

“We are confident that JCCs around the country are taking the necessary security protections, and that law enforcement officials are making their investigation of these threats a high priority,” said ADL Chief Executive Jonathan A. Greenblatt in a statement.

The FBI and Department of Justice have said they are “investigating possible civil rights violations in connection with the threats” to JCCs.

This story has been updated with information on a JCC in Cleveland which was also threatened on Monday as well as some additional statements from the Secure Community Network and ADL.