A 17-year-old boy suffered injuries to his head and body in the incident which took place at around 8.10pm yesterday, January 2, at West Cross Shopping Centre on Oldbury Road.
West Midlands Police were called to the shopping centre following reports of a group of men who had entered a store with weapons.
The 17-year-old was repeatedly struck and was taken to hospital.
His injuries are not believed to be life-threatening.
The group of men fled the scene following the incident and officers are now appealing for anyone with information about the disorder to come forward.
In a statement, West Midlands Police said: “Officers are reviewing CCTV footage and as part of our enquiries we would like to speak to anyone who may have been in the area at the time.
“If you have any information about the incident please contact us via Live Chat on our website or call 101 quoting 20/101827/25.
“Alternatively, to pass on information anonymously please contact Crimestoppers on 0800 555 111.”