Six people, including a police officer, have been killed in a shootout in New Jersey.
The officer was investigating a murder in Jersey City when he approached two suspects, one of whom opened fire and shot him in the head, police sources told NBC News.
The two suspects then fled in a rental van and were holed up in a grocery store where a fierce gun battle broke out, according to reports.
Jersey City Police Chief Michael Kelly said the shootings started at a cemetery where the officer was gunned down, and continued at a kosher supermarket where five more bodies were found.
Both suspects and three civilians were killed, according to authorities.
“Our officers were under fire for hours,” Mr Kelly told a news conference.
He would not say exactly what set off the shooting but that he believes the officer who was killed was trying to stop some “bad guys”.
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Jersey City Mayor Steven Fulop named the officer who was killed as married father-of-five Joe Seals.
“He was a great cop,” the mayor said.
“He probably is responsible for more guns being removed from the streets than any.
“He was an officer that loved JC, was involved in the city, and one that everyone knew regardless of their precinct.
“Our thoughts and prayers are with Joe’s family during this Christmas season and beyond.
“We take for granted sometimes the selfless work a police officer does when they wear that uniform.
“In the end they are people that volunteered to keep everyone else safe regardless of the circumstance.”
A second officer was wounded after being struck in the shoulder by gunfire, and two others were injured by shrapnel, Mr Fulop said.
SWAT teams, state police and federal agents responded to the incident, with officers blocking off an area which included a school, the kosher supermarket and a hair salon.
All schools in Jersey City were put on lockdown.
Authorities have said the incident is not believed to be a terror attack.
US President Donald Trump tweeted: “Just received a briefing on the horrific shootout that took place in Jersey City, NJ.
“Our thoughts & prayers are [with] the victims & their families during this very difficult & tragic time.
“We will continue to monitor the situation as we assist local & state officials on the ground.”