A violent uprising at a Mexican prison where at least 52 inmates died is being investigated by government officials as revelations of anarchy behind prison walls are revealed.

FOX's Gurnal Scott has the story:

The deaths from clashes of rival factions within the Topo Chico prison in Monterrey, come as a government report details evidence of inmate-controlled facilities and widespread corruption.

Witnesses to this riot report fires at the facility and inmates trying to get back into the fight. The clash comes less than a week before Pope Francis is scheduled to visit another of the nation's jails.

Thursday's riot deaths come after a similar incident four years ago this month at another facility where 44 inmates died and a number of guards were accused of helping other inmates escape during the chaos. 

Gurnal Scott, FOX News.