An argument in a residence on Chicago's South Side early Tuesday erupted into gunfire, leaving four people dead and four others injured, police said.
The shooting happened at 5:42 a.m., police said, and no arrests were immediately made. Police had few details about the victims, but it appeared that none of them were juveniles.
Identities of the dead weren't immediately released.
The four injured included a 25-year-old man who was shot in the back of the head and another man who was shot in the back of the head. Their conditions were unknown, according to police.
A 23-year-old man who was shot in the back and a woman who suffered an unspecified gunshot wound were both in critical condition, police said.
Additional reporting by The Associated Press.