SIERRA VISTA — The Mojave Unit at the state prison facility in Douglas remained locked down Thursday afternoon.

The lockdown continued a day after unrest at the prison.

Nolberto Machiche, spokesman for the Arizona Department of Corrections, said the cause of the unrest is still under investigation.

Six inmates were transported for medical attention — at least one of them by air — after what the Department of Corrections public affairs office described again Thursday as  different fights that occurred at about the same time Wednesday morning.

The prison staff responded to the incident about 10 a.m.

The Douglas Fire Department was called to the prison complex about 10:30 a.m. and waited nearby at the Bisbee-Douglas International Airport for prison medics to bring out injured people.

The Elfrida Fire Department also provided assistance.

As of 3:30 p.m. Thursday, five of the six inmates transported for medical attention had been treated and released, and they had been returned to the Douglas prison facility, Machiche said.

The identity, location, type of injury and condition of the inmate who remained at a hospital was not released because of the Department of Corrections’ civil liability oversight for U.S. Health Insurance Portability and Accountability Act rules, Machiche said.

Machiche said the incident involved only Latino inmates, but commented no further on the reasons for or circumstances surrounding Wednesday’s violence.

Whether the confrontations among the inmates were caused by incidental commingling of unfriendly subpopulations, Machiche was yet unable to say.

“We are, as a department, looking at the best ways to best maximize bed space as the population increases, so we’re constantly moving inmates around,” he said. “The motive of it still remains unknown. We don’t know what the true motive was. We’re still conducting investigation, and until it’s complete, we won’t know what happened.”

Interviews of all inmates involved are being conducted as part of the investigation, Machiche said.

The Mojave Unit is a 920-bed medium security facility at the prison at 6911 N. BDI Blvd.

There are also four minimum-security facilities that have a total of 1,781 beds.