All Oklahoma prisons remain on lockdown Tuesday as Department of Corrections continues to investigate coordinated, gang-related fights that broke out at six facilities over the weekend, resulting in 36 injuries and one death.

The investigation has yielded numerous seizures of contraband cellphones, weapons and drugs by agency staff, while also shedding new light on what took place, DOC officials said Tuesday.

The fights, which began Saturday, took place at Northeast Oklahoma Correctional Center in Vinita; Lawton Correctional Facility; North Fork Correctional Center in Sayre; Dick Conner Correctional Center in Hominy; Mack Alford Correctional Center in Stringtown; and William S. Key Correctional Center in Fort Supply.