Batches of inmates will be transferred from Bedford jail "throughout the day" following Sunday's riot, a prison official has said.
The first prisoners were taken away late on Sunday night after the disturbance was resolved, she added.
The Prison Service is investigating the cause of the riot which took police and specialist guards six hours to get under control.
Up to 200 inmates were thought to have been involved in the incident at the Category B facility, which was "successfully resolved" at around 11.30pm.
Private contractor trucks waited outside the compound early on Monday morning, flanked by police vehicles, including a dog unit.
Several police vans marked as carrying chemicals including "irritants", "flammable liquid" and "compressed gas" also lined up outside the jail walls.