(Reuters) - Law enforcement said they were making progress on Saturday ending a disturbance at a federal correctional facility in southern Texas were as many as 2,000 inmates were protesting medical services, according to a published report.

The disturbance began early Friday at the Willacy County Correctional Center, which primarily holds immigrants who entered the United States illegally, and is run by the private company Management & Training Corp, the San Antonio Express-News reported.

The prison facility in Raymondville is about 40 miles (64 km) from the Mexican border.

The unrest, which prison officials said was not a riot, began when prisoners refused to come to breakfast or report for work to protest medical services at the facility, the Express-News and local broadcaster KGBT-TV reported.

The inmates broke out of their housing structures and converged in the recreation yard, setting fire to several kevlar domes, or tents, that serve as prison housing, the newspaper said.

Management & Training Corp could not immediately be reached for comment about the standoff.

By Saturday afternoon, the disturbance was almost under control, the newspaper said, citing the Willacy County sheriff and a prison spokesman.

Authorities said there had been no serious injuries during the 36-hour standoff.

The Texas Department of Public Safety, the Willacy County Sheriff’s Office, Texas Highway Patrol troopers, Texas Rangers, and other agencies remained at the facility, the newspaper said.