NEW YORK: Police waged an hours-long gunfight with two men armed with high-powered rifles on Tuesday in and around a New Jersey cemetery and kosher market, leaving six people dead, including one officer and both suspects, authorities said.

The violence began after noon in the heart of Jersey City, the state’s second-largest municipality directly across the Hudson River from Lower Manhattan, prompting a lockdown of all Jersey City schools as law enforcement swarmed the area.

Police arriving on the scene immediately came under “high-powered rifle fire,” Jersey City Police Chief Michael Kelly told reporters.

While the gunmen’s motives were not known, there was no immediate evidence the bloodshed was either a hate crime or terror-related, Kelly said, adding, “but that’s certainly on the table.” Investigators believe the two suspects, who were not yet identified, acted alone, officials said.

“Based on what we now know, there are no ongoing threats to public safety that have any connections to today’s events,” Governor Phil Murphy said at a separate news conference.

“This has been an incredibly tough day for Jersey City and the entire state of New Jersey.” The two gunmen and three victims believed to be bystanders were pronounced dead inside the JC Kosher Supermarket. The slain police detective was fatally wounded near a cemetery about a mile away where the shooting apparently started when he tried to intercept one of the suspects, Kelly said Kelly said he believed the civilians and the detective were all struck by gunfire from the suspects, who arrived in a stolen U-Haul truck and held police at bay around the store for hours before the shooting ended.

“Their movement was rapid and continuous for four hours within that area,” the chief said at an news briefing. He described the crime scene as “very extensive,” encompassing at least three locations. Hundreds of rounds were fired, he said.

BOMB SQUAD CALLED IN

Kelly said investigators believed the U-Haul vehicle contained what may have been an “incendiary device,” which he said was removed and taken away for examination by police bomb squad personnel.

Two more police officers and a civilian were wounded but were reported in stable condition, the Hudson County Prosecutor’s Office posted on Twitter. Police said the two wounded officers were later released from the hospital.

The officer who died was identified as Joe Seals, a married father of five who had been with the Jersey City force since 2006, Mayor Steven Fulop told reporters. Kelly said Seals was in his 40s.

Investigators believed the grocery where the shooting ended was randomly singled out by the gunmen, the New York Times reported. Some local media reported the initial confrontation between the suspects and police near the cemetery was linked to a previous homicide investigation.

The ensuing standoff prompted a massive law enforcement deployment with local SWAT teams and federal agents rushing to the scene, as well as officers from the neighbouring New York City Police Department.

“Oh my god, it’s like a movie. It’s crazy. ... Nothing I’ve ever seen before. I’m still shaking,” an unidentified resident of the area told NBC’s New York affiliate.

Kelly said the incident occurred in an “up and coming” neighbourhood of Jersey City, a racially mixed town of about 265,000 residents.

“This neighbourhood has had challenges. It has become a much safer, much better neighbourhood over the last two years, three years or so,” the police chief said. “We can only say folks that live in the neighbourhood support the police department. They were out there today showing support.”

US President Donald Trump said on Twitter: “Just received a briefing on the horrific shoot-out that took place in Jersey City, NJ. Our thoughts & prayers are w/ the victims & their families during this very difficult & tragic time.