The NYPD is investigating nine possible anti-Semitic attacks in the last two weeks.
"We are investigating them thoroughly with our hate crimes task force," Harrison said. "We treat them very seriously and we make sure that our investigators do their best to do what we can to bring the individuals to justice."
The most recent attack was on Friday morning, when three women, ranging in age from 22 to 31, were allegedly slapped by another woman, Harrison said.
The alleged assailant was arrested and told investigators that she committed the crime because she thought they were Jewish, the chief added.
The unidentified woman was charged with first-degree harassment as a hate crime.
Police released surveillance video on Saturday from a an attack on Wednesday when a 40-year-old man was punched in the face. The victim suffered a cut to his lip and refused medical attention, police said.
Mayor Bill de Blasio said the NYPD has increased visibility in the areas where the attacks occurred.
"Anti-Semitism is an attack on the values of our city — and we will confront it head-on," he tweeted.