Dec. 22 (UPI) -- Thirteen people were injured by gunfire in Chicago on Sunday morning, Area South Chicago Police said.
The shooting took place at 12:35 a.m. during a gathering at a house in Chicago's South Side, police said.
Seven people were transported from the scene with injuries stemming from gunshots and six others transported themselves. The victims' ages ranged from 16 to 48, Chicago Police Chief of Patrol Fred Waller said.
A 16-year-old boy was transported to the hospital in critical condition but has since stabilized and four people remained in critical condition.
Two suspects are in custody and are being questioned about the incident.
"One person was arrested at the scene with a revolver," said Waller. "Another person who was shot during the altercation was later identified as a person who may have also been firing a weapon."
The Chicago Police Department said in a statement it has charged Marciano White, 37, with illegally using a weapon as a convicted felon. Police said he was seen leaving the scene with a bag clutched to his body and as officers approached him, he allegedly attempted to elude them.
Shots were first fired inside a residence as a result of a dispute among people attending a memorial from someone who was killed in April and as people began to leave the residence gunfire continued outside, Waller said.
"This is an isolated incident that stemmed from inside that part and flowed onto the street," Waller said. "Shots were fired inside, everyone started to leave and that's when shots were fired outside."
Chicago Mayor Lori Lightfoot called the shooting "a terrible act of cowardice."
After meeting with the victims at the hospital, Lightfoot told reporters during a press conference that it was a terrible tragedy, urging anyone with information to contact the authorities.
"We can't normalize this kind of behavior and tragedy in our city," she said.
Detectives are investigating the incident.