A police line band is seen as recovery and cleanup crews arrive at the JC Kosher Supermarket in the aftermath of a mass shooting on 11 December 2019 in Jersey City, New Jersey. (AFP)

A shooting at a kosher deli in a New York suburb was fueled by anti-Semitism and a hatred of police, authorities said Thursday, the latest in a rash of attacks against Jewish targets in recent years.

Investigators had previously stopped short of characterizing Tuesday’s firefight in Jersey City, in which six people were killed including the two suspects, as motivated by anti-Semitism.

But on Thursday, New Jersey attorney general Gurbir Grewal told journalists: “We believe the suspects held views that reflected hatred of Jewish people as well as hatred of law enforcement officers.”

Grewal also said authorities had evidence that the suspects had expressed interest in the fringe Black Hebrew Israelite movement, which has voiced hostility toward Jewish people.

The now-deceased suspects — identified as David Anderson, 47, and Francine Graham, 50, who reportedly lived together — shot dead a police officer at a cemetery near a kosher market before storming the deli, killing two customers and a cashier before they died in a hail of police gunfire.

“I can confirm that we’re investigating this matter of potential acts of domestic terrorism fueled both by anti-Semitism and anti-law enforcement beliefs,” Grewal said.

He said all three of the people killed in the store — two of them members of the area’s Hasidic community — were shot within minutes of the gunmen entering.

A fourth person was wounded by gunshot but escaped the deli.

Grewal said officers thus far had recovered five firearms, four inside the deli and one in a vehicle parked outside the store.

One of the guns found in the shop was an “AR-15 style weapon,” which investigators believe Anderson was firing as he entered the market.

They also found a shotgun and several semi-automatic pistols, and traced two of the weapons back to purchases Graham had made in Ohio in 2018.

Hundreds of police, including tactical officers armed with rifles and wearing olive-green fatigues and helmets, were deployed during the hours-long gun battle.

Officials discovered a live pipe bomb in the van, as well as “documentary evidence” they would not classify as a “manifesto,” as many US media outlets have done.

According to The New York Times, a note found in the vehicle did not suggest a clear motive but did indicate that Anderson believed he was acting in “God’s will.”

The Black Hebrew Israelites are a group of black Americans who consider themselves descendants of ancient Israelites. The movement has splintered into many semi-autonomous groups and does not have a link to mainstream Judaism.

The movement is known for provocative demonstrations but is not generally considered a promoter of violence, though the Southern Poverty Law Center, which tracks extremist groups, has labeled it a hate group, saying that bigotry informs its ideology.

It does not, however, have a violent track record on the scale of US white supremacists, which in recent years have grown more active and committed deadly attacks.

This week’s shooting is the latest targeting Jewish people in recent years, part of an uptick in anti-Semitic acts both in the United States and in Europe.

Last year, a white supremacist entered a Pittsburgh synagogue and killed 11 people, the deadliest attack ever committed against the Jewish community in the United States.

In October, the eastern German city of Halle suffered a deadly anti-Semitic gun rampage on the holy day of Yom Kippur. A synagogue was the primary target.

Tuesday’s shooting set off an outpouring of emotion in Jersey City, a city across the river from lower Manhattan with 270,000 residents, including a small community of Hasidic families who have settled there in recent years.

Hundreds of people attended a Wednesday evening funeral for one of the victims, identified as the wife of the deli owner.

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.

Bill de Blasio — the mayor of New York, home to the largest population of Jewish people outside of Israel — said Tuesday’s attack was a “warning sign.”

“People are now living in constant fear,” he told journalists Wednesday, citing a “crisis of anti-Semitism” in the city and the nation.