A prison riot Wednesday killed at least 23 inmates in the northern Mexican state of Durango, which has been the scene of increasingly violent feuding between drug-trafficking groups during the last year.
Authorities said fighting broke out early in the morning between inmates affiliated with rival drug-trafficking groups who were held in the penitentiary in the state capital, also named Durango. The clashes left an undetermined number of inmates injured.
The Durango state prosecutor, Daniel Garcia Leal, declined in a radio interview to identify the rival cartels. But the state has been a battleground between a trafficking group led by Joaquin "El Chapo" Guzman, from the northwestern state of Sinaloa, and a competing gang known as the Zetas.
The same Durango prison was the site of a riot in March in which seven inmates died.
Wednesday's riot marked the latest violence in Mexican prisons, which are notoriously overcrowded and prone to fights and uprisings over living conditions.
Rioting in a separate prison in the Durango city of Gomez Palacio in August left 20 dead from knife wounds and gunshots. In March, gang brawling in a facility in the border city of Ciudad Juarez killed 20.
Mexican prisons have grown more crowded and dangerous as the government carries out a war against cartels, with more than 67,000 drug arrests in three years. The increased incarcerations have often created an incendiary mix by jamming members of rival gangs inside the same walls.
The penal facilities also have seen dramatic breakout attempts as drug gangs seek to rescue captured members, sometimes with success.
In May, a convoy of men dressed in what appeared to be police uniforms cruised into a prison in the northern state of Zacatecas and calmly led 53 inmates to freedom as surveillance cameras rolled. Authorities said it was an inside job.
Durango is part of an important drug-trafficking corridor known as the Golden Triangle, which also consists of areas in the states of Chihuahua, a smuggling hub on the U.S. border, and Sinaloa, the cradle of Mexican drug trafficking.
Durango has become one of Mexico's most dangerous regions for cartel clashes, with more than 600 people slain last year, according to the Reforma newspaper.
Among the dead was Agustin Roberto "Bobby" Salcedo, an assistant principal and school board member in the Los Angeles suburb of El Monte. The bodies of Salcedo and five other men were found after they were hauled out of a bar Dec. 30 in Gomez Palacio, his wife's hometown. The killings remain unsolved.