Inmates from Bedford jail will be transferred to other prisons "throughout the day" following Sunday's riot, a prison official said.
The first prisoners were taken away late on Sunday night after the disturbance was resolved, she added.
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.
It took riot police more than six hours to get the outbreak - which began at about 5pm on Sunday - under control.
Around 200 inmates are thought to have been involved in the disturbance.
There were reports of loud bangs and explosions coming from the Category B jail and prison officers reportedly retreated to a "safe place".
The riot comes just a few months after inspector strongly criticised HMP Bedford. The watchdog said inmates had claimed it was easier to get hold of drugs than clothes or bedsheets.
Physical condition of the prison was described as poor, with many inmates living in cramped conditions. The report detailed damaged furniture, graffiti, shortages of clothing and dirty, unscreened showers.
The report also said: "Arrangements for managing violent and bullying behaviour and supporting victims were weak."