NEW YORK (CBSNewYork) – A Post-It note reading “Hitler Is Coming” was plastered onto a billboard designed for visitors to leave positive messages at the Jewish Children’s Museum in Crown Heights on Tuesday night.

The disturbing anti-Semitic display in an area where children congregate has many in the neighborhood rattled and angry, reports CBSN New York’s Scott Rapoport.

Devorah Halberstam, the museum’s co-founder who’s son was killed in a terrorist attack on the Brooklyn Bridge in 1994, is appalled.

“It’s extremely, extremely horrible,” she said. “It’s devastating to the museum I represent.”

Dov Hikind, a longtime New York State assemblyman and a perennial Jewish community leader, says the anti-Semitism he is seeing is more than alarming.

“It’s like war on the Jewish people, that’s what it’s like,” he said. “We have never seen anything like what is happening now.”

In reaction, Gov. Andrew Cuomo is ordering the state police Hate Crimes Task Force to assist in the investigation.

“I am disgusted by the anti-Semitic message,” said Cuomo.

This incident is just the latest in a disturbing string of anti-Semitic incidents in Brooklyn this month alone:
* A Crown Heights resident was verbally assaulted.
* A Jewish man in Williamsburg slapped so hard his hat flies off.
* Four suspects wanted by police for allegedly punching a 42-year-old Jewish man in the head while shouting anti-Jewish slurs.

The latest numbers from the NYPD show a 67 percent increase in hate crimes since the beginning of the year.

“There’s a lot of fear right now in the Jewish community in Brooklyn, and they’re not sure whats next for them,” said Evan Bernstein, New York / New Jersey regional director for the Anti-Defamation League.

Mayor Bill de Blasio addressed the incident via Twitter, posting “Imagine being a child who went to this mural for inspiration only to find this vile message. A wave of hatred has been allowed to fester in our society, but it ends in our city.”

The NYPD says it is aware of the anti-Jewish note at the Children’s Museum, but that it is not officially being labeled a hate crime yet.

They point out the museum asks for messages to be posted so technically they say it is not vandalism.