Ten people, including a child, were killed when a riot erupted during family visiting hours at a prison in the northwestern Mexican state of Sinaloa on Thursday, Oct. 8, 2026, state authorities said.
The violence broke out that morning at the El Castillo Penitentiary in the port city of Mazatlan. The Sinaloa Public Security Secretariat said on X that nine inmates and one family member died, while 16 prisoners were taken for medical treatment after being injured. The secretariat described the incident as “a brawl occurred inside the prison facilities,” without detailing what set it off.
Sinuhe Tellez, Sinaloa’s secretary of public security, said in a video posted on social media that “nine inmates and a minor who was visiting lost their lives, and 16 inmates were injured.”
Gunfire Heard Beyond the Perimeter
Local media reported that inmates used firearms during the fight. The sound of gunshots from inside the walls can be heard in footage recorded outside the jail’s perimeter. Authorities have not yet said how the deaths occurred.
Outside the penitentiary, soldiers stood guard, including at least one vehicle carrying a mounted machine gun. Police officers gathered in front of the facility, and relatives of inmates were photographed standing near Mexican navy officers and speaking with them as the chaos unfolded behind the walls.
Troops Move in to Restore Order
Members of the army, the National Guard, the navy and state security forces entered the prison following the clash to regain control of the grounds. Mexico’s federal security cabinet said the penitentiary, which houses 1,800 inmates, is now “under control.”
Prosecutors will investigate what caused the riot.
A Prison System Under Strain
Overcrowding has long been identified as a driver of bloodshed behind bars in Mexico. Analysts point to the heavy use of pretrial detention, which keeps thousands of prisoners locked up without a sentence, along with a shortage of prison staff, as conditions that have fed corruption and violence inside the country’s lockups.
Mexico has 276 prisons, among them 14 federal penitentiaries and 249 state prisons. The country’s prison population stood at 261,388 people as of February, according to official figures.
El Castillo is not the first Sinaloa lockup to erupt. A riot at a prison in Culiacan, the state capital, left seven inmates dead and another injured.
Cartel Warfare Grips Sinaloa
The state has been a battleground for rival wings of the Sinaloa drug-trafficking cartel. Violence surged in September 2024 amid an internal power struggle between two factions, pitting the sons of convicted former drug lord Joaquín “El Chapo” Guzmán, known as “Los Chapitos,” against followers of Ismael “El Mayo” Zambada, another former cartel leader who has been detained.
The bloodshed has made Sinaloa one of six Mexican states that the U.S. State Department tells Americans not to visit because of security concerns. Mazatlan, a Pacific resort and shipping hub, sits at the southern end of a state where shootouts, roadblocks and disappearances have become routine features of daily life.
The riot also lands at a politically delicate moment. Mexico’s government is facing pressure from the Trump administration to intensify its campaign against the cartels, a demand that has put the security situation in states such as Sinaloa under intense scrutiny on both sides of the border.
For now, the toll from El Castillo stands at nine inmates and one visitor dead, with 16 prisoners hurt and the facility back in the hands of the authorities. What turned a routine visiting day into a massacre remains for prosecutors to determine.
