There is growing concern that a New Jersey kosher supermarket was deliberately targeted in a gun rampage that killed two Strictly Orthodox Jews and a police officer.

Investigators looking into Tuesday’s deadly shooting said it was unclear if antisemitism was a motive for the attack in Jersey City’s Greenville neighbourhood, which is home to a small Charedi community.

But the New York Times reported one of the suspects had published antisemitic, anti-police posts online, while the city’s mayor said the kosher store had been targeted.

Local media in the US state reported the attack began several blocks away when the fallen police officer, Joseph Seals, approached two suspects in connection to a murder investigation.

The unidentified man and woman opened fire on the detective, killing him, and fled in a hire truck to the JC Kosher Supermarket on Martin Luther King Jr Drive.

The duo then barricaded themselves and killed three people inside the store.

“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.

“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."

40 terrified children took shelter in a Chasidic school directly next door as more than 100 rounds were fired in a gunfight with police that raged for several hours.

All schools across the city were placed on lockdown and public transport was suspended. Hatzalah paramedics were among those responding to the stand-off.

Two of the victims inside the store were named as members of the Chasidic community: Leah Mindel Ferencz, of Jersey City, who owned the kosher store with her husband, and Moshe Hirsch Deutsch, 24, from Brooklyn.

A third victim, previously unidentified and reported to be another member of the Greenville community, was named as Miguel Jason Rodriguez, a migrant from Ecuador.

The attackers, at least one of whom had a weapon resembling an assault rifle, also died in the gunfight.

As the investigation in NJ continues to unfold, evidence indicates that this attack was motivated by anti-Semitism.

This is horrifying.

Jews have been attacked, beaten, & killed, simply because of our religion.

I will continue to update as info becomes available.@NYCMayor

— Councilman Deutsch (@ChaimDeutsch) December 11, 2019

The kosher store is adjacent to the school and a small synagogue as part of a growing community that has attrackted approximately 100 Chasidic families, according to New Jersey Chabad.

Steven Fulop, the mayor of Jersey City, tweeted on Wednesday morning that an “extensive review” of CCTV footage had made clear the two individuals had targeted the kosher store.

He added in a further tweet: “I’m Jewish and proud to live in a community like Jersey City that has always welcomed everyone. It is the home of Ellis Island and has always been the golden door to America.

“Hate and antisemitism have never had a place here in JC and will never have a place in our city.”