Police have been called to a prison in Bedford following reports of a riot.
Emergency services were called to the prison in the town centre at around 5pm.
A police spokeswoman said: "Bedfordshire Police is currently assisting HMP Bedford following reports of unrest within the prison.
"We were called shortly before 5pm and have a number of officers at the scene working with prison staff to resolve the issue."
It was reported that prisoners started a riot and have taken over parts of the category B prison.
A Prison Service spokesman said: "Specially trained staff are working with the emergency services to resolve an ongoing incident involving a number of prisoners at HMP Bedford.
"We are absolutely clear that prisoners who behave in this way will be punished and could spend significantly longer behind bars."
Ambulance and fire services are also on standby outside the prison.
A spokesman for the East of England Ambulance Service said: "We are at the scene on standby at this stage. It's an on-going incident. We are not in the prison."