BOSTON — The number of anti-Semitic incidents in Massachusetts increased dramatically in 2017 when compared to the previous year, a Jewish civil rights group reported Tuesday.

There were 177 anti-Semitic incidents reported in 79 Massachusetts communities last year, up 42 percent from 2016, the Anti-Defamation League said in a statement.

“Record numbers of communities are being impacted by anti-Semitism as disseminating hate becomes increasingly mainstream,” ADL New England Regional Director Robert Trestan said.

The incidents included harassment, vandalism, school threats, and threats made against Jewish institutions.

An 86 percent increase in anti-Semitic incidents at the state’s schools is particularly troubling, the organization said. There were 93 reported incidents occurring in schools, compared with 50 in 2016.

In response, the ADL significantly expanded its anti-bias peer training and professional development programs, which has now reached more than 100 schools. The ADL’s Education Department provides trainings and resources across New England, reaching thousands of students, faculty and staff each year.

Among the examples of anti-Semitism in 2017 cited by the organization were vandalism to Boston’s Holocaust Memorial; knocked over headstones in the state’s third-oldest Jewish cemetery in Melrose; and white nationalist fliers distributed at Clark University in Worcester.

Acts of vandalism are concerning because they indicate that people feel emboldened enough to break the law, the ADL said.

The ADL’s annual numbers are based on anti-Semitic incidents reported to the organization’s New England office.