An incident at a prison in northern Mexico early Thursday — described by some as a riot or escape plot — has left dozens dead and wounded, according to local media reports.
Local news outlets showed video of flames rising from the Topo Chico prison in Monterrey, Nuevo Leon state, overnight. State and federal forces, as well as relatives of inmates, amassed outside the site Thursday.
Reports in leading local news outlets said at least 50 people died and 30 were injured in a riot or escape attempt, citing unnamed security officials.
CNN has not independently confirmed the circumstances of the incident.
The Nuevo Leon state government, via Twitter, denied there was a prison break and cautioned about reporting death tolls before the investigation is complete. Officials announced a news conference for Thursday morning but later postponed it.
Prison violence in Mexico
Mexico has seen deadly riots and other prison violence in the past.
At the same prison in Monterrey, three inmates were stabbed to death in February 2012.
That same month, 44 inmates were killed and 30 escaped in a riot at a prison in Apodaca, which is not far from Monterrey. Security officials blamed that incident on a fierce rivalry between drug cartels inside that prison.
In 2011, the head of security at the Topo Chico prison was found dead and mutilated. Authorities at the time said that a note, presumably from a drug cartel, was left with the body.