MEXICO CITY (AP) — Mexican soldiers and state police regained control of a state prison in Ciudad Juarez across the border from El Paso, Texas after violence broke out early Sunday, according to state officials.

The Chihuahua state prosecutor’s office said in a brief statement that its personnel were investigating, but did not provide details and did not immediately confirm rumored deaths.

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 wherein authorities only maintain nominal control. Clashes regularly erupt among the inmates of rival gangs, which in places like Juarez serve as proxies for drug cartels.