At least 20 people are reported dead in a prison riot early today in the northern city of Apodaca, Mexico, reported the Associated Press.
Government officials said prisoners started the fight by setting their matresses on fire, reported Reuters, sparking early morning violence that spread to a second prison cell.
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Officials said the prison, which is located near the industrial city of Monterrey, has since been secured.
Some 50,000 people have been killed over the past five years in drug-related violence in Mexico.
Criminal activity has spread to the country's heavily corrupt prison system, according to Reuters, leading to several deadly riots in prisons in recent years.