CHICAGO—Three teenagers and a 12-year-old were among six people who were shot outside a party in Chicago and treated at hospitals for their injuries, police said. Someone opened fire from an SUV on a group of people standing on a sidewalk late Saturday, news outlets reported. The injured included a 12-year-old girl who was shot in the hand; two girls aged 13 and 14 who were shot in their lower backs; a 15-year-old girl who was shot in the lower back and grazed on her head; a 19-year-old woman who was wounded in the lower back; and a 25-year-old man who walked into a hospital with a gunshot wound to the lower back and was treated and released. No suspects or arrests were immediately announced. It was unclear what prompted the shooting.