JERSEY CITY, NJ – Six people, including a police officer and three bystanders, were killed in a furious gun battle Tuesday that filled the streets of Jersey City with the sound of heavy fire for hours, authorities said. The dead included the two gunmen, Jersey City Police Chief Michael Kelly said. Authorities believe the Jewish market was targeted by the gunmen, Jersey City Mayor Steven Fulop tweeted Tuesday night. “It's a really tough day for the city of Jersey City,” Fulop said. The kosher grocery is a central fixture in a growing community of Orthodox Jews who have been moving to Jersey City in recent years.