New Delhi, June 9 -- A mass shooting incident that left at least 12 people injured on 6 June at an Ohio summer festival stemmed from "a dispute involving two rival groups," according to police.

On Tuesday, Police Chief Michael Troendle said that a dispute between rival groups led to a physical altercation that ultimately escalated into an exchange of gunfire, NBC News reported.

Earlier on 6 June, at least two gunmen fired shots just after 5:30 PM near the Old West End Festival in Toledo, police said over the weekend. A dozen people were hurt, with the oldest victim reported to be 61 years old and the youngest 14 years old, police Lt. Dan Gerken said, noting that most were in their early 20s.

As of 7 June, all 12 victims were in stable ...