A 37-year-old suspect appeared in a New York court on Sunday charged with five counts of attempted murder over a stabbing spree at a rabbi's suburban house -- the latest in a spate of attacks on Jewish targets.

Thomas Grafton allegedly entered the property in Monsey, Rockland County, during celebrations on Saturday evening for the Jewish festival of Hanukkah, knifing several people with a machete before fleeing.

He was held in custody after appearing in Ramapo Town Court, where he denied the charges.

The frenzied attack was quickly condemned as a "domestic terrorism" incident that underscored growing anti-Semitic violence in the United States.

"It is domestic terrorism. These are people who intend to create mass harm, mass violence -- generate fear based on race, color, creed," New York Governor Andrew Cuomo told reporters at the scene on Sunday.

Former vice president and current Democratic presidential challenger Joe Biden tweeted that "the horrifying rise of antisemitism is tearing apart the fabric of our communities and the soul of this nation. We've got to stand together as a country and fight these flames of hatred."

No official details were released about the victims, who were rushed to nearby hospitals. Local media said one person was seriously injured.

Grafton was reportedly arrested in his own car about 30 miles (50 kilometers) away two hours after the attack.

'Everyone was screaming'

One witness to the horror told how the weapon had a big handle and the attacker "swung it back and forth."

"Everyone was screaming and panicking and shouting 'out out out.' It was chaos," Joseph Gluck, 30, told reporters.

Last year a white supremacist walked into a Pittsburgh synagogue and killed 11 people -- the deadliest attack against the Jewish community in the United States.

And earlier this month six people, including the two attackers, were killed in a Jersey City shooting at a kosher deli, which authorities said was fueled in part by anti-Semitism.

A report in April from the Anti-Defamation League (ADL) stated that the number of anti-Semitic attacks in 2018 was close to the record of 2017, with 1,879 incidents.

"I was praying for my life," said Aron Kohn, 65, another witness to Saturday's attack who compared the knife used by the assailant to "the size of a broomstick."

Kohn threw chairs and tables in an attempt to head off the assault.

"I saw him stabbing people," he added. "He injured a guy, he was bleeding in his hand, all over."

Kohn said the attacker tried to enter the adjacent synagogue, but it was locked.

Yossi Gestetner, of the Orthodox Jewish Public Affairs Council (OJPAC), told The New York Times that one of the victims was a son of the rabbi.

"The house had many dozens of people in there," Gestetner said. "It was a Hanukkah celebration."

Rockland has the largest Jewish population per capita of any US county, with 31.4 percent, or 90,000 Jewish residents.

Surge in hate crimes

In response to the recent surge in hate crimes in New York, Mayor Bill de Blasio announced on Friday that the NYPD was stepping up patrols in three neighborhoods and increasing visits to places of worship.

After Saturday's attack, the mayor tweeted that he had recently spoken to longtime Jewish friends who were fearful of outwardly showing their faith.

"We will NOT allow this to become the new normal," he wrote. "We'll use every tool we have to stop these attacks once and for all."

In Israel, Prime Minister Binyamin Netanyahu said the country "strongly condemns the recent displays of antisemitism including the vicious attack at the home of a rabbi in Monsey, New York."

"We will cooperate however possible with the local authorities in order to assist in defeating this phenomenon."

The attack happened at about 10:00 pm on Saturday, the seventh night of Hanukkah, with about 100 people gathered for a candle-lighting ceremony.

"It's a wave and a trend of hate-filled violence that is sweeping the country, not just NY State," tweeted Maya Wiley, a civil rights activist and senior vice president for social justice at the New School private university in New York. "We have to stand together to keep our neighbors safe."

At Thomas's court appearance, bail was set at $5 million and he was then taken in handcuffs to a police vehicle and driven to Rockland County Jail.