An inmate died and two guards were wounded in a fight at a prison in Durango, a state in northern Mexico, the Public Safety Secretariat said.
Federal Police officers found grenades, assault rifles, pistols, ammunition and marijuana during a search conducted Wednesday after order was restored at the prison.
Officers were sent to penitentiary No. 1 in Durango city, the state capital, to stop a gunfight between rival inmates.
The officers seized 14 handguns, three rifles, including two AK-47s, four fragmentation grenades, 28 ammunition clips, 510 rounds of ammunition, eight cell phones, a laptop computer, 135 doses of marijuana and 13,000 pesos (about $1,000) in cash.
Rodolfo Rodriguez Carranza, the prison’s chief guard, was arrested for allowing arms and drugs to enter the facility.
Thirty of the 70 inmates identified as having participated in the fight will be transferred to a federal prison, the secretariat said.
Mexico’s penitentiary system has long struggled to control imprisoned drug traffickers and other gangsters, who bribe officials to obtain what they want, with the case of Sinaloa cartel boss Joaquin “El Chapo” (Shorty) Guzman being a clear example of the problem.
Guzman, who was arrested in Guatemala in 1993, pulled off a Hollywood-style jailbreak when he escaped from the Puente Grande maximum-security prison in the western state of Jalisco on Jan. 19, 2001.
The drug lord, considered extremely violent, is one of the most-wanted criminals in Mexico and the United States, where the Drug Enforcement Administration has offered a reward of $5 million for him.
During his time in prison, Guzman enjoyed privileges and amenities ranging from electronics to prostitutes, media investigations found.
The warden during Guzman’s stay at Puente Grande was released from prison in 2010 after serving a nine-year sentence for aiding the escape.