WAUWATOSA, Wis. (AP) — Authorities say they arrested a 15-year-old boy in connection to a shooting at a suburban Milwaukee mall that injured eight people.

Wauwatosa Police Chief Barry Weber says the shooting happened during an altercation Friday afternoon between two groups. He said four “innocent bystanders” suffered what were believed to be non-life threatening injuries.

Police say the suspect ran out of the mall alongside other people. The mall was closed Saturday and investigators were on scene overnight. Shoppers were allowed back on Sunday.