Four people were killed and three injured in a Saturday morning shooting at an illegal gambling site in Brooklyn, New York police said.

The shooting happened before 7 a.m. on Utica Avenue in the Crown Heights area, NYPD Chief of Detectives Dermot F. Shea said at a media briefing Saturday.

Shea described the scene as "chaotic" when officers first responded.

Two firearms were recovered and there's evidence of at least 15 shots fired, he said, adding that more firearms may be found.

The victims range in age from 32 to 49 years old. Four men died, and two men and one woman were injured. He described their injuries as non life-threatening and said they are receiving treatment at a hospital.

He said the families of the victims had not been notified but that two victims appeared to live outside New York while the others lived throughout Brooklyn.

An eighth person was injured in the leg while trying to flee the location, he said.

No arrests have been made.

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Shea said it's too early to say what caused the shooting or if was a gambling dispute or a robbery. He said there's "nothing to indicate" it's gang-related.

The site has had no history of complaints over the last couple of years, police said.

The unlicensed club, identified as the “Triple A Aces Private & Social Event Space,” was operating on the first floor of an older wood-frame townhouse on a block with some empty storefronts and boarded-up buildings, the Associated Press reports.

"I’ve said it before and I’ll say it until I can’t anymore: we have an epidemic of gun violence that spares no community — and it won’t stop until we get guns off our streets once and for all," Mayor Bill de Blasio said in a tweet Saturday morning.

Despite a recent decline in homicides in the city, Saturday's shooting was the second mass killing in New York in a week. Last Saturday, four homeless men in Manhattan were found beaten to death, and a fifth wounded, in what police called a random attack.

Contributing: Grace Hauck, USA TODAY; The Associated Press