West Yorkshire Police have arrested a 16-year-old boy on suspicion of assault.
A 15-year-old boy was assaulted in Centenary Square on Sunday and footage of the incident which was circulated on social media appears to show the victim being repeatedly kicked in the head.
On Thursday the force tweeted: "We are aware of footage circulating of an incident in Bradford city centre.
"We are making enquiries into this footage to establish when this incident occurred and to identify those involved.
"Thanks to all those who brought it to our attention."
The victim was treated for minor injuries.
Police said the suspect was released on bail and enquiries are ongoing.