(CNN) -- Authorities in western Oklahoma said Tuesday they were responding to a prison riot at the North Fork Correctional Facility, where multiple injuries were reported.
A morgue had been set up in a tent outside the prison, according to a witness, though there had been no reports of deaths.
More than 20 people, all inmates, were injured in the riot and at least five were flown to area hospitals, according to Julie Heavrin of Air Evac Lifeteam. She said she had no information regarding their conditions.
However, Beckham County sheriff spokeswoman Amy Brewer said that just eight inmates were injured.
Aerial video of the scene from CNN affiliate KOCO showed armed officials holding prisoners at gunpoint.
The riot started shortly before noon and it was not clear what motivated it, said Brewer. She said the Oklahoma Highway Patrol had six crews on the scene and Beckham County sheriff's deputies were assisting.
The prison is located in Sayre, about halfway between Oklahoma City and Amarillo, Texas.
Ronnie Harold, Sayre's police chief, said his department was providing security for the prison, which can house up to 2,400 inmates.
"We are still at a standstill. The prison guards are doing their job inside and we still have the perimeter secured," he said.