NEW ORLEANS (AP) - New Orleans officials are quite sure someone knows the identities of the shooters who opened fire on each other in a crowd of hundreds of people during a block party - and they're urging them to come forward.

Police Superintendent Michael Harrison says the shootout that wounded 17 people Sunday night was probably gang-related. He said it's "highly possible" that the shooting was related to the city's heroin trade but authorities are still investigating.

New Orleans Mayor Mitch Landrieu told a news conference Monday that given the number of people at the playground when the shooting broke out, it's "pretty clear that people do know" who the shooters are.

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