(JTA) – Anti-Semitic incidents in the United States rose by more than one-third in 2016 and shot up 86 percent in the first three months of 2017, the Anti-Defamation League reported.

There has been a massive increase in harassment of American Jews, largely since November, and at least 34 incidents linked to the presidential election in November, the ADL reported Monday in its annual Audit of Anti-Semitic incidents.

There were a total of 1,266 acts targeting Jews and Jewish institutions during 2016, a 34 percent increase of incidents of assaults, vandalism, and harassment over the previous year. Nearly 30 percent of those incidents, or 369 of them, occurred in November and December.

The acts included 720 harassment and threat incidents, an increase of 41 percent over 2015; 510 vandalism incidents, an increase of 35 percent; and 36 physical assault incidents, a decrease of 35 percent.

There are preliminary reports of 541 anti-Semitic incidents for the first quarter of 2017. One reason for the jump in incidents in the first quarter of 2017 appears to be the bomb threats called in to Jewish community centers and other Jewish institutions around the country, mostly by an Israeli-American teen who has been arrested in Israel and charged in the U.S.

The 541 anti-Semitic incidents so far in 2017 include: 380 harassment incidents, including the 161 bomb threats, an increase of 127 percent over the same quarter in 2016; 155 vandalism incidents, including three cemetery desecrations, an increase of 36 percent; and six physical assault incidents, a decrease of 40 percent.

“What’s most concerning is the fact that the numbers have accelerated over the past five months,” ADL CEO Jonathan A. Greenblatt said in a statement. “Clearly, we have work to do and need to bring more urgency to the fight.”

The states with the highest number of incidents were those with large Jewish populations, including California, New York, New Jersey, Florida and Massachusetts.

While incidents on college campuses stayed mostly static, after nearly doubling in 2015, incidents in non-Jewish elementary, middle and high schools increased 106 percent from 114 in 2015 to 235 in 2016, with another 95 incidents reported for the beginning of 2017.