Police in northern Nigeria have released hundreds of captives who were beaten, abused and held in squalid conditions at an Islamic boarding school in Katsina.

Nearly 300 men and boys from 7 to 40 years of age had been at the facility where police said they discovered “inhuman and degrading treatments” following a raid to free the remaining students.

67 of the inmates who were freed by the police were shackled in chains, and many were taken to hospital for treatment, police are now working to reunite the captives with their families.