At least 17 people were killed when inmates tried to escape from a prison in northern Mexico Tuesday, firing guns at guard towers and running through tunnels below the facility. The dead included 11 inmates and six guards, Durango state public safety officials said in a statement. The violence broke out around 5 p.m. (local time) Tuesday at a prison in the city of Gomez Palacio when prisoners began to riot and opened fire, officials said. "The inmates started to shoot with firearms toward the guard towers and the guard areas," the statement was quoted as saying by CNN. Officials said the clashes occurred as guards worked to stop a "massive prison break."