Desecration of grave sites at cemeteries in Philadelphia and outside St. Louis. Swastikas etched on cars in Miami Beach. Bomb threats forcing evacuation of Jewish community centers.

Another wave of intimidation targeting Jewish communities swept across the nation Monday, and community leaders and law enforcement struggled to stop it.

There were 31 bomb threats Monday, called into 23 community centers and eight Jewish day schools, the JCC Association of North America said. Mark Potok, senior fellow at the Southern Poverty Law Center, said the events marked the fifth series of attacks already this year.

“I have been here more than 20 years and I’ve never seen anything like it,” Potok said. “There are provocateurs out there who say that if you don’t like somebody, go after them.”

White House spokesman Sean Spicer said Monday that President Trump was “deeply disappointed and concerned” by the cemetery vandalism and other acts.

“The president continues to condemn these and any other forms of anti-Semitic and hateful acts in the strongest terms,” Spicer said.

But Potok and Anti-Defamation League CEO Jonathan Greenblatt say Trump has failed to consistently speak out against anti-Semitic rhetoric.

“I think, in large part, the election of Donald Trump let the genie of anti-Semitism out of the bottle,” Potok said. “And it’s not going to go back in easily.”

Philly vandals damage Jewish gravesites
Bomb threats again rattle Jewish centers
Greenblatt said Monday’s threats raised the total this year to about 90. No bombs have been found.

In Wilmington, Del., Democratic Sen. Tom Carper was meeting with Jewish community leaders at the Siegel Jewish Community Center to discuss the climate of threats and violence when someone called in a bomb threat. The center was evacuated, police investigated, and programs resumed a short time later.

“It is heartbreaking for such a flash of fear to overtake a place of strong community and joy that brings together people of all ages under one roof — from the babies in the day care center to the senior citizens taking part in exercise classes,” Carper said. “These acts must end.”

Joe Nicoletti and Ronni Newton of Taconey Holmesburg town watch group pay their respects at a damaged headstone in Mount Carmel Cemetery Feb. 27, 2017, in Philadelphia. More than 100 headstones were vandalized at the Jewish cemetery in Philadelphia, damage discovered less than a week after similar vandalism in Missouri. Jacqueline Larma, AP

Joe Nicoletti and Ronni Newton of Taconey Holmesburg