Cincinnati police said nine people were wounded in a shooting early Sunday at a crowded nightclub and concert venue, and they have not made arrests yet. Interim police chief Adam Hennie said the wounded were taken to hospitals and that none of the injuries were life-threatening, speaking at a news conference as investigators worked the scene.

Hennie said the shooting occurred at about 1 a.m. at Riverfront Live, where he estimated that between 500 and 600 people were inside when the shots rang out. He declined to provide additional details about what happened, citing the integrity of the investigation, and said no arrests were made immediately following the shooting.

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives said it was helping with the investigation, as local authorities continue to gather information about the incident.