The Brooklyn Heights neighborhood is reeling after 19 anti-Semitic markings were found scrawled on synagogues and homes there just days before the Jewish festival of Sukkot.

Swastikas spray-painted on the steps of local synagogues were discovered as congregants filed into classes on Monday evening, while crude leaflets marked with the Nazi symbol and derogatory slurs were stuffed under the windshields of vehicles.

After canvassing the area yesterday morning, police found more than a dozen other markings on and around Remsen Street, in the heart of Brooklyn Heights.

The swastika “represents the deaths of 6 million people. It’s very destructive,” a rabbi of Congregation B’nai Avraham, Aaron Raskin, said.

Rabbi Raskin said he found a swastika painted on the outside steps leading to the synagogue Monday night. It was the first such incident he knew of in the neighborhood, he said.

The Brooklyn Heights Synagogue was also vandalized, and its executive director, Randi Jaffe, said she had given footage from security cameras that may show the perpetrators to police.

She added that she had covered up markings yesterday morning so that children who attend school at the synagogue wouldn’t see it. “It’s a difficult thing to explain to 3-year-olds,” she said.

New York State logs the most anti-Semitic incidents in the country, according to an annual report released by the Anti-Defamation League in March. Last year, there were 119 incidents of harassment, threats, and assaults against Jewish people and 165 incidents of anti-Semitic vandalism in the state.

Although anti-Semitic vandalism and attacks have dropped off both in New York and nationally during the past decade, the ADL’s New York director, Joel Levy, said a rash of incidents was reported in Long Island in the weeks before the Jewish high holidays this year. According to NYPD statistics, bias crimes in general are up slightly this year. There have been 192 hate incidents this year, compared with 181 in the same period last year.

Mr. Levy, Rabbi Raskin, and several local politicians suggested the Brooklyn Heights incidents could be linked to the presence of President Ahmadinejad of Iran in the city this week.

“I think the president of Iran arriving to New York spurred these hatemongers to come out of the closet,” Rabbi Raskin said.

Mr. Ahmadinejad spoke at Columbia University on the day of the Brooklyn Heights incidents. He was asked about his views on Israel, which in the past he has said should be destroyed, and the Holocaust, which he has called a “myth.”

The mayor’s community affairs commissioner, Nazli Parvizi, said the motive was unclear. “Regardless of who is here, things happen,” she said, calling the attacks “vandalism at its worst.”

The attacks appeared to be random and not specifically targeted at the homes of Jewish residents, Ms. Parvizi said.

As of yesterday evening, police had not yet identified any suspects. A police task force with 20 extra investigators is investigating the vandalism as a possible hate crime.

The NYPD anti-graffiti unit was brought in yesterday to paint over the markings.

“That swastika is not graffiti,” a state Assembly member from Brooklyn, Dov Hikind, whose mother is a Holocaust survivor, said. “That swastika is the ultimate symbol of hate.”