Officers received reports of a stabbing just before 10pm at a residence in Monsey, which is around an hour north of New York City, Ramapo Police Chief Brad Weidel said.
He added that five people were taken to hospitals for treatment though the extent of their injuries is not known.
The officer later confirmed a suspect had been arrested while a vehicle of interest had also been located.
The incident is said to have taken place at the house of a Hasidic rabbi while they were celebrating the Jewish festival Hanukkah, according to the Orthodox Jewish Public Affairs Council (OJPAC) for the Hudson Valley region.
The attacker, the group said, was wearing a scarf.
Photos and videos posted on social media show a large emergency response with paramedics running and pushing stretchers.
The NYPD Counterterrorism Bureau said it was "closely monitoring the reports" though New York State Attorney General Leticia James said: "I am deeply disturbed by the situation unfolding in Monsey, New York tonight."
She continued: "There is zero tolerance for acts of hate of any kind and we will continue to monitor this horrific situation.
"I stand with the Jewish community tonight and every night."
New York City's police department said it was stepping up patrols in heavily-populated Jewish neighbourhoods, such as Monsey in Rockland County, following a spate of antisemitic attacks over the past year including one that left a rabbi dead.
Earlier this month six people, including a police officer, died in a shooting at a kosher market in northern New Jersey.
https://news.sky.com/story/multiple-people-stabbed-at-hanukkah-celebrations-in-new-york-11897047
