A mass shooting overnight at a club in Brooklyn left three people dead and another nine wounded, police officials and the mayor said Sunday morning.

A 19-year-old gunman with no criminal history sparked a gang-related mass shooting at a Brooklyn lounge when he opened fire ... grainy video footage recovered by cops from inside Taste of the City Lounge on Franklin Ave. in Crown Heights.

Within minutes, officers arrived, finding that nine men and three women, ranging in age from 19 to 61, had been shot. Three men died. Marvin St. Louis, 19, was pronounced dead at the scene. Amadou Diallo, 27, and Jamel Childs, 35, were critically wounded and succumbed to their injuries at the hospital.

Around four shooters opened fire at a New York City restaurant early Sunday, resulting in three deaths and eight injuries. According to police, the violence is gang-related.

Jamel Andre Childs, 35, tried to cool tempers down at Taste of the City lounge in Crown Heights before the gunfight erupted, friends say.