MEXICO CITY — A fight between two inmates at a penitentiary in the northern Mexican city of Monterrey escalated into a riot early Thursday that left 52 prisoners dead, the state governor said.
The trouble began just before midnight local time at Topo Chico Prison when the two men, identified only as Jorge Ivan "N" and Juan Pedro "N," began fighting, said Gov. Jaime Rodríguez Calderón of Nuevo León.
As the violence spread, prisoners set fire to the prison warehouse.
It remained unclear precisely how the inmates had died.
Twelve inmates were reported injured in the uproar at the prison, the oldest in Nuevo León.
Initial news reports said that the riot had broken out as part of an escape attempt, but the government said on its Twitter feed that none of the inmates had escaped.
"We are living through tragedy due to the conditions in the prisons," Rodríguez said at a news conference in Monterrey.
Forces from the federal police, the marines and the army surrounded the prison, the governor said, as relatives of the inmates gathered outside awaiting news.
The riot was brought under control around 1:30 a.m., the state government said on Twitter.
Mexican prisons are vastly overcrowded and riots frequently break out. In September, a leader of the Zetas drug gang was stabbed to death at Topo Chico in a riot that left 11 inmates wounded.
In February of 2012, 44 prisoners were bludgeoned and stabbed to death as guards stood by in a state prison in Apodaca, in the Monterrey suburbs, in a riot initiated by the Zetas. As the Zetas killed inmates from their rivals in the Gulf cartel, 30 Zeta leaders escaped.
The month before, 31 inmates died in a prison in the neighboring state of Tamaulipas in fighting between Zetas and the Gulf cartel.