Officers are investigating the reports of ‘unrest’ within HMP Bedford yesterday.
Police were called to support colleagues at the prison shortly before 5pm and a number of officers from Bedfordshire, Cambridgeshire, Hertfordshire and Essex attended the scene, along with other emergency services.
The incident was resolved shortly after 11pm.
Three men aged 39, 37 and 26 have been arrested on suspicion of committing offences under the Prison Security Act 1992.
They currently remain in police custody as officers continue to investigate the circumstances of the incident.
Two prisoners were taken to hospital during the incident, one of whom had fallen unwell and one who had sustained minor injuries during the unrest.
Both have been treated and have returned to the prison.