An inmate hospitalized after a weekend outburst of violence at a prison in Oklahoma died of his injuries, the company that owns and operates the prison said on Sunday, bringing the number of dead from the episode to four.

The prisoner, a man, had been taken to the hospital after an “inmate-on-inmate altercation,” said Steve Owen, a spokesman for Corrections Corporation of America, which owns the Cimarron Correctional Facility in Cushing, Okla.

Three more inmates remained hospitalized in stable condition, he said.

The violence took place Saturday night in one of the prison’s housing pods, the company said in a statement on Sunday. The altercation lasted only two minutes, but it took prison staff members 38 minutes to secure the area, prison officials said. No staff members were injured, Mr. Owen said.

The prison remained on lockdown on Sunday while the episode was investigated. Mr. Owen said.

It was the second time in four months that those measures were put in effect in response to violence. The prison was locked down for several weeks after a large fight in June resulted in 11 inmates being sent to the hospital with injuries, said Alex Gerszewski, a spokesman for the Oklahoma Department of Corrections.