Shots fired in New Jersey: ‘Sounds like a war zone’

A MAJOR police operation is underway in the heart of Jersey City where a volley of shots have been fired and several people are dead in scenes reminiscent of a "war zone".

Jersey City mayor Steven Fulop said there were "multiple deceased" inside a commercial building on Martin Luther King Drive. At least six people have been killed, including one police officer, three civilians, and the two suspected shooters, officials confirmed. The slain police officer was not immediately identified.

Another two police officers and at least one civilian were wounded and are expected to survive, according to Hudson County prosecutor's office.

Police initially said the two suspects were a man and a woman but have not yet provided further details or a possible motive.

A New Jersey City Police officer told news.com.au the situation was "too active" for him to immediately comment on.

Jersey City Director of Public Safety James Shea said the incident was not believed to be terror-related.

Preliminary reports indicated that the incident unfolded when an officer approached one of the suspects in connection with an investigation into an earlier homicide and was shot dead, according to a person with knowledge of the matter, the New York Times reports.

The pair then fled in a van and eventually ended up at JC Kosher supermarket where at least one of them opened fire.

The sounds of rapid gunfire ringing out on the street have been captured on video and shared widely on social media. Witnesses, including CBS News journalist Alice Gainer, described hearing "at least 100 shots" fired over about one hour. NBC News reports a police officer described the attack as an "ambush".

Another witness described how the shooting started.

"I was standing by the salad bar in the grocery and I heard three shots, bullets shattered the glass of the grocery," said one witness in the store, according to Chabad.org, a Jewish news source.

"Suddenly I saw two people come in, with long black raincoats and long guns. They tried to point the gun at me, I pushed it away and ran away."

Heavily armed local and state officers in SWAT trucks swarmed the scene, aiming their guns in every direction, knocking on doors and ushering residents and business owners to safety, and ducking behind doorways and shop entrances - some even crawling along footpaths, closely pressed to the ground - as they zeroed in on the store. The Bureau of Alcohol, Tobacco, Firearms and Explosives is also responding to the situation.

"We need a lot of prayers right now for Jersey City officers. Keep all those involved in your thoughts," the New Jersey State Policemen's Benevolent Association tweeted.

All nearby schools were placed on lockdown and police ordered members of the public and media to leave the area as helicopters circled overhead.

New Jersey Transit Police "are assisting Jersey City with an active shooting incident within the area of the west side branch", the department said in a tweet.

"Stay clear of the area until further notice.

"HBLR service is suspended. ALL bus service on the West Side Branch is suspended updates to follow."

Jersey City is located in the state of New Jersey across the Hudson River from Manhattan, New York City. It's the second most populous city in NJ with a population of roughly 265,000.

New Jersey Governor Phil Murphy wrote on Twitter, "I have been briefed on the unfolding situation in jersey City. our thoughts and prayers are with the men and women of the Jersey City Police Department, especially with the officers shot during this standoff, and with the residents and school children currently under lockdown."

All students and staff are safe, according to the Jersey City school district.

"All students and staff are safe however ALL school are currently on lockdown due to police activity," the school district tweeted.

US President Donald Trump has been briefed on the shooting and continues to monitor the situation, he said in a tweet.