A violent confrontation erupted Thursday morning at the El Castillo Penitentiary in Mazatlan, a city in the northwestern Mexican state of Sinaloa, resulting in multiple fatalities. State officials reported that the clash took place during family visiting hours and led to the deaths of nine inmates and one visitor.

The Public Security Secretariat of Sinaloa confirmed via social media that 16 inmates were injured and required medical attention following the incident. Local reports indicated that firearms were used during the altercation, although authorities have not provided specific details on how the fatalities occurred.

To regain control of the facility, which houses approximately 1,800 prisoners, security forces including the army, National Guard, navy, and state police were deployed. Mexico’s federal security cabinet stated that the prison is now under control following the response.

Sinaloa, a state long affected by drug-related violence and organized crime, has witnessed repeated security challenges within its penal institutions. The circumstances leading to the deadly riot remain under investigation.