Quote: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.

Jewish sites reported at least 16 bomb threats, said Mark Potok, senior fellow at the Southern Poverty Law Center. The latest series of attacks was the fifth 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.