Dozens Dead in Mexico Prison Riot Governor says 52 prisoners were killed By Arden Dier, Newser Staff Posted Feb 11, 2016 8:42 AM CST Updated Feb 11, 2016 9:40 AM CST 10 comments Comments It may have been sparked by an escape attempt. (Twitter) (Newser) – Scores of inmates at a prison in the Mexican city of Monterrey are dead following a predawn riot on Thursday. The state governor in Nuevo Leon says 52 were killed and 12 more injured, reports the AP. Gunshots and explosions were reportedly heard from within the prison, where a fire broke out, apparently after an escape attempt, per the BBC. Relatives on-site for conjugal visits reported seeing inmates with burns. A public security rep in the state of Nuevo Leon says the riot began around midnight, noting, "The authorities formed a security cordon and nobody escaped. Everything was under control at 1:30am." Local media, however, reported seeing police vehicles combing the streets near the prison in search of possible escapees. The riot comes only a day before Pope Francis is scheduled to arrive for his first papal visit to Mexico. He plans to visit a notorious prison in Ciudad Juarez, once considered one of the most violent cities in the world, next week.