Police officer among dead in gun battle in US city

A police officer and multiple other people were killed in a furious gun battle that filled the streets of a US city with the sound of heavy gunfire for about an hour, authorities said.

Authorities said they believe the shootout in Jersey City, New Jersey was not an act of terrorism, but the bloodshed was still under investigation.

Officials gave no immediate details on what set off the shooting and how it unfolded, and there was no word on how many suspects were involved or whether anyone had been taken into custody.

Shooting in New Jersey
An antit-errorism unit arrives at the scene of a shooting in Jersey City (Eduardo Munoz Alvarez/AP)

One officer was pronounced dead at a hospital, and multiple other people were found dead at a kosher supermarket, Mayor Steven Fulop said without specifying how many were killed.

A second officer was struck in the shoulder by gunfire, and two others were hit by shrapnel, Mr Fulop said.

President Donald Trump tweeted: "Just received a briefing on the horrific shootout that took place in Jersey City, NJ. Our thoughts & prayers are w/ 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."