WASHINGTON -- At least three people died in a shooting early Friday in the US state of New Jersey, local law enforcement officials said.

The shooting occurred inside a Pathmark supermarket in Old Bridge, a suburb about 40 km from the city of New York, local TV channel NBC 4 New York reported.

Among the dead was an 18-year-old woman, while another, a 23-year-old man, was believed to be the gunman, local authorities said. Details about the other victim remained unknown. The motive behind the shooting and how the shooter was killed was not immediately clear.

However, the New York-locaed TV channel WABC-TV reported the suspect was a former Marine who worked at the supermarket. He returned to the supermarket in the early morning with an AK-47 rifle and an automatic handgun and killed two people. He then shot himself when confronted by police.

Old Bridge Mayor Owen Henry told NewJersey.com it was the worst phone call a mayor could receive.

The supermarket, which usually opens at 6 am weekdays, was closed.

The latest incident follows a shootout in New York City on August 24, in which a gunmen was killed by police and nine bystanders were wounded.