LEBANON, Ohio (AP) — A southwest Ohio grand jury has issued indictments against 11 inmates involved in a large fight at a state prison last summer.

The Warren County Prosecutor’s Office said Monday that each of the inmates is charged with two counts of aggravated riot stemming from the July 22 incident at Warren Correctional Institution in Lebanon.

The Ohio State Highway Patrol said the fight started over use of a dayroom telephone. It escalated into a large brawl with many of the participating inmates affiliated with two prison gangs, the Aryan Brotherhood and Cincinnati Wild Boys.

If convicted, each inmate could have three years tacked onto their sentences.

The prison, with 1,390 inmates, is one of the most violent in the state in terms of number of assaults.