Activities at 11 Jewish community centers around the country were interrupted on Monday by calls reporting bomb threats.
The threats were found to be hoaxes, the Jewish Community Center Association of North America said, but the group added it's become a troubling pattern. Since the beginning of 2017, the group has tracked 69 instances of bomb threats. The FBI has opened an investigation.
"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," David Posner of the association said in a statement.
The series of threats began on Jan. 9, with other threats recorded on Jan. 18 and Jan. 31 as well as Monday. Employees and those attending classes and events were evacuated as local police responded to check for any sign of explosive devices. The threats were made to centers in 27 states as well as one Canadian province.
"Our JCCs are strongly rooted in communities across the country, and we will not be cowed by threats intended to disrupt people’s lives or the vital role Jewish community centers play as gathering places, schools, camps, and fitness and recreation centers," Posner said.
As a show of support, the Council on American–Islamic Relations offered a reward of $5,000 for information leading to the arrest and conviction of whoever was responsible.
"It is the duty of American Muslims to offer support to the Jewish community and any minority group targeted in the recent spike in hate crimes nationwide," CAIR Executive Director Nihad Awad said in a statement, adding that Jewish leaders have shown support to Muslim victims of hate crimes. "We hope this reward will aid in the swift apprehension and prosecution of the perpetrators."
The threats were also condemned by the Anti-Defamation League, which called on political leaders to speak out against anti-Semitism. In a response to a question from a Jewish reporter last week about a rise in anti-Semitism, President Donald Trump initially called him a liar and told him to sit down. Trump then said that he was "the least anti-Semitic person," and he blamed any anti-Semitic messages on "the other side."
On Monday, White House press secretary Sean Spicer said Trump has made it clear that hate-motivated actions are "unacceptable."
"Hatred and hate-motivated violence of any kind have no place in a country founded on the promise of individuals freedom. The President has made it abundantly clear that these actions are unacceptable," Spicer said in a statement.
Meanwhile, Chelsea Clinton called for Trump to more explicitly condemn acts of anti-Semitism.
The president's daughter Ivanka Trump, who converted to Judaism, tweeted on Monday that she believed in religious tolerance.
"We must protect our houses of worship & religious centers," she said.