Overview
- Reports say rival inmate groups exchanged gunfire inside the Centro Penitenciario de El Castillo, prompting an internal confrontation.
- State and federal security forces entered the prison and strengthened the exterior perimeter with support from the Army, the National Guard and Armed Forces aviation.
- Authorities declared control of the facility and allowed seven Red Cross ambulances into the complex while visits were suspended as a precaution.
- Local outlets have circulated claims of deaths and injuries but the numbers remain unconfirmed pending an official toll from the Secretaría de Seguridad Pública de Sinaloa.
- Officials are conducting module-by-module searches to find weapons and to establish how any arms could have entered the prison, and families of inmates are awaiting formal updates.