Harassment, vandalism and other hostile acts against Jewish people and sites in the U.S. increased by 34 percent last year and are up 86 percent through the first three months of 2017, according to data released on Monday.

A spate of bomb threats against Jewish community centers and schools, and vandalism at Jewish cemeteries in the U.S. this year have contributed to the surge, according to the Anti-Defamation Leagues report.

There have been more than 100 bomb threats against 75 Jewish community centers and eight Jewish day schools around the country this year through early March. Vandals have toppled headstones and inflicted other damage at Jewish graveyards in St. Louis , Philadelphia and other cities this year. A swastika made from feces besmirched an art school bathroom in Rhode Island.

What the data tells us is incontrovertible and why the Jewish community describes such heightened anxiety, ADL CEO Jonathan Greenblatt told The Huffington Post. Theres no doubt that theres a high degree of anxiety.

Greenblatt added that his organizations report, which was released on Holocaust Remembrance Day, shows that public officials must do more to denounce anti-Semitism and find ways to make Jewish-Americans feel secure.