More than half of the hate crimes reported in New York City this year have been antisemitic, said New York Police Department officials on Wednesday, according to CNN. The latest report covers incidents through September 1.Most of the incidents reported were acts of vandalism, such as graffiti or swastikas on places like synagogues, according to NYC Chief of Detectives Dermot Shea. The "vast majority" of the incidents do not involve personal action and assault, said Shea, although some reports of assault were filed. Overall, antisemitic hate crimes in NYC are up 63% in 2019 compared to last year. So far there have been 152 reports of antisemitic hate crimes this year, while last year there were only 93 incidents reported in the same period, reported CNN.Altogether there have been 290 reports of hate crimes this year. Last year there were 205 reports. Arrests concerning hate crimes have also gone up with 135 arrests so far this year compared with 108 over the same period last year.There's no definitive cause for the rise in hate crimes and antisemitic incidents, according to Shea.In a number of the cases of antisemitic hate crimes this year, mental illness has been a factor, while in other cases there were "some people that just hate," said Shea.At least three antisemitic assaults occurred in the past two weeks in New York City.“We won’t tolerate hatred or violence against our Jewish community,” Mayor Bill de Blasio tweeted on Aug. 30, after a Jewish man had rocks thrown at him.“I wouldn’t say it’s a huge increase, no,” said a supervisor for the Shomrim, a private Orthodox volunteer security organization that coordinates with the New York Police Department.“These kinds of incidents had been happening before,” the supervisor said. “Regarding antisemitism, it’s been happening before also, but in a way every incident is being looked at now differently because everyone’s mind is on antisemitism now.”“What we do see is an increase in assaults,” he said. “If it’s antisemitism, I can’t tell you. It looks like antisemitism when you watch a video. Is it actually antisemitism? Who knows?”Ben Sales/JTA contributed to this report.