Ten guards and four inmates are dead after gunmen in armoured vehicles attacked a state prison in Ciudad Juarez across the US border from El Paso, Texas.
The Chihuahua state prosecutor's office said in a statement that about 7am on Sunday various armoured vehicles arrived at the prison and gunmen opened fire on guards.
In addition to those killed, 13 people were wounded and at least 24 inmates escaped.
Mexican soldiers and state police regained control of the prison later on Sunday. The state prosecutor's office said its personnel were investigating.
In August, a riot inside the same state prison spread to the streets of Juarez in violence that left 11 people dead.
In that case, two inmates were killed inside the prison and then alleged gang members started shooting up the town, including killing four employees of a radio station who were doing a promotion at a restaurant.
Violence is frequent in Mexican prisons, including in some where authorities only maintain nominal control.
Clashes regularly erupt among inmate of rival gangs, which in places like Juarez serve as proxies for drug cartels.
Shortly before Sunday's attack on the prison, municipal police were attacked and managed to capture four men after a pursuit, according to the state prosecutor's office statement. Later, police killed two alleged gunmen travelling in a SUV.