(JTA) — The United Kingdom’s main watchdog group on anti-Semitism reported a record 1,309 incidents in 2016, constituting a 36 percent increase over the 2015 tally.

Of the anti-Semitic incidents recorded last year by the Community Security Trust, or CST, 107 were cases of physical assault, compared to 87 in 2015, the report published Thursday said.

While the 2016 figure in the assault category was the highest since 2010, the bulk of incidents – 1,006 of them – belonged to the “verbal and written anti-Semitic abuse” category, which covers emails, letters, text messages and tweets.

The increase is not attributable to any specific trigger, as has been the case in years when fighting broke out between Israel and its enemies, the report said. Instead, CST cited a “combination of events and factors,” including an unprecedented public debate about anti-Semitism within the Labour Party, terrorist attacks in Western countries and the June referendum in which a majority of voters supported a British exit from the European Union.

“CST did record a small number of anti-Semitic incidents during 2016 that made direct reference to the European Union or to Brexit, but not enough to explain, on their own, the overall high total for the year,” the report said in reference to the referendum, which British police said triggered a slew of hate crimes, though not many against Jews.

“These events, and their subsequent discussion in mainstream and social media, provided material and motivation for anti-Semitic hate incident offenders,” CST wrote.

Another factor driving the increase is the growing awareness to the importance of reporting anti-Semitic incidents, CST noted, though it is still likely “that there is significant underreporting of anti-Semitic incidents,” CST wrote.

One assault in January 2016 in London involved six Jewish schoolgirls wearing Jewish school uniforms who, on their way home from school, were assaulted and verbally abused by two older girls, one of whom appeared to be wearing a Muslim headscarf. The offenders shouted, “You f***ing Jews.”

In another, also in January in London, three white men were said to have thrown laughing gas canisters at four visibly Jewish victims while shouting “Heil Hitler.”

The assault category, which was the second-most prevalent in 2016, was closely followed by the Threats rubric, with 100 incidents of anti-Semitic threats made against Jews, and Damage and Desecration to Jewish Property, with 81 cases.

The CST report identified 758 distinct targets of attacks last year, with more than half of them being individuals. There were also 96 homes and 64 synagogues targeted.

A description of perpetrators’ ethnicity was available in 499 of the 1,309 recorded incidents. Of those, 55 percent were white, northern Europeans and 40 percent were African, South Asian and Arab. In the Netherlands and France, a majority of anti-Semitic attacks were perpetrated by people with immigrant backgrounds from countries with large Muslim populations, according to Jewish community watchdogs in those countries.

In a statement, Jonathan Arkush, the president of the Board of Deputies of British Jews, called the CST data “deeply worrying, particularly in light of the fact that there was no single trigger event in 2016.”

Separately, the board on Wednesday expressed its satisfaction with the findings of an internal probe at University College London of an anti-Israel riot that broke out in October and prevented an Israeli speaker, Hen Mazzig, from appearing. As violent protesters overwhelmed campus security, Mazzig had to be escorted out of the lecture room disguised as a guard.

“This was a serious incident that represents a failure of the UCL Code of Practice on Freedom of Speech to adequately protect freedom of expression on campus,” said the internal probe, which was published Wednesday.