Dozens of people were killed in a prison riot in northeastern Mexico early on Thursday, local media reported.
Milenio TV said at least 50 people were killed in the predawn riot, and that some prisoners may have escaped. It said relatives of prisoners had heard gunshots in the early hours and that a blaze had broken out.
Television images showed police vehicles patrolling the streets near the prison.
Milenio reported that inmates' relatives who had been within the jail's premises for conjugal visits had seen inmates with burns, and that authorities were scouring for escapees.
The Nuevo Leon state government said on Twitter the situation had been brought under control, but gave no details on what had happened at the Topo Chico prison.
The incident is the latest in a series of deadly riots in recent years to rock the country's overcrowded prisons, which often house inmates from different drug gangs.
