WAUWATOSA, Wis. — A 15-year-old boy was arrested in connection to a shooting at a suburban Milwaukee mall that injured eight people, authorities said.

Wauwatosa Police Chief Barry Weber said the shooting happened during a dispute Friday afternoon between two groups. He said four “innocent bystanders” suffered what were believed to be non-life threatening injuries. Investigators said the suspect ran out of the mall alongside other other people.

“We do know there was some sort of altercation, and that’s when the bullets started flying,” Weber said during a press conference Sunday.

The name of the suspect has not been released, and authorities didn’t announce charges Sunday. Investigators say they have recovered a firearm.