JERSEY CITY, New Jersey — Sacred Heart Catholic School in Jersey City remained closed Dec. 11, the day after a gun battle involving two men around a kosher supermarket across the street from the school.

Six people, including a police detective and three customers in the supermarket, were killed in a furious battle that filled the streets of Jersey City with the sound of heavy gunfire for hours, authorities said.

The school was placed on lockdown during the nearby attack. None of the students was hurt.

Sacred Heart was scheduled to reopen Dec. 12 and counselors would be onsite to assist students and staff, according to a statement from the Archdiocese of Newark.

“We are grateful for the immediate response by staff in handling this terrifying situation with all the students. All the children are safe, and parents were notified yesterday in a timely fashion,” the statement said. “We reiterate our gratitude to all the first responders in safeguarding the public during this deadly incident.”

It added that “as a Catholic community, we continue to grieve for the victims and for the family of Jersey City Police Detective Joseph Seals.”

News reports said Seals was shot at the Bay View Cemetery in Jersey City, allegedly by two suspects, who then fled to the kosher market, where they killed three customers and injured a fourth customer. They also shot and injured two other police officers. The suspects were later found dead inside the store.

The Hudson County Prosecutor’s Office said Seals was transported to a nearby hospital, where he died. Seals, a husband and father of five children, was a 15-year veteran of the Jersey City Police Department.

Jersey City Mayor Steven Fulop said in a tweet: “Based on our initial investigation (which is ongoing) we now believe the active shooters targeted the location they attacked. Due to an excess of caution, the community may see additional police resources in the days/weeks ahead. We have no indication there are any further threats.”

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