HMP Ranby was described as "in crisis" by the Chief Inspector of Prisons Nick Hardwick after a critical report was released about the institution.
Following an unannounced 11-day inspection by HM Inspectorate of Prisons in March, the report found two prisoners died through "self-inflicted deaths" last year, and a further two have died in a similar way since then.
Conditions in part of the prison, which holds more than 1,000 men, were described as dirty and prisoners were found to have climbed netting in a bid to force a transfer to another facility.
Nearly half the population said they had felt unsafe having been victimised or intimidated, findings showed.
Evidence was also found of an increasing number of incidences of self-harm at the category C training prison, and the availability of legal highs was also found to have increased.
Chief Inspector of Prisons Nick Hardwick said the report showed a prison "in crisis".
Sixty prisoners are "actively involved" in the disturbance at HMP Ranby after twice as many inmates refused to return to their cells, the Prison Officers' Association (POA) has said.
At around 12.30pm 120 prisoners refused to return to their cells. They have taken control of a unit.
We have got national resources at the prison trying to establish a surrender plan. We know 60 prisoners have been actively involved.
Mr Travis said today's disturbance was "no surprise" to the POA.
It's all down to chronic staff shortfalls and a management that are hell-bent on delivering things they can't deliver safely.
Prisoners are saying 'We're not dealing with this'. They will react.
An ongoing disturbance is taking place at HMP Ranby in Nottinghamshire after 120 inmates refused to return to their cells.
The Prison Officers' Association confirmed the "serious incident" began at 12.30pm with minor damage caused but no injuries to staff or prisoners.
Two men have died after a light aircraft crashed into a field near the M1 in Nottinghamshire.
A Nottinghamshire Police spokeswoman said: "Two men have died after a plane, in which they were travelling, came down in a field.
"Inspectors from the Air Accidents Investigation Branch have been deployed to the scene to commence an investigation."
A light aircraft has crashed in a field in Nottinghamshire near the M1.
Police said there were two casualties in the crash at around 1.30pm today.
An eyewitness told ITV Central that he saw the plane "lose control and nosedive" into the field near junction 26 of the M1.
Air accident investigators have launched an inquiry into the incident.
For more on this story, visit ITV Central
Tim Sperry, who manages a bingo hall on Hucknall High Street, said his customers told him there was a man in the nearby snooker club with a gun:
Mr Sperry described the scene:
Basically, there's a guy in the snooker hall with a gun and he's said that the only way he'll come out is shooting.
So at the moment, there are about seven armed police stood outside the bingo hall in body armour, helmets and carrying sub machine guns and they're telling us to stay inside and lock the doors.
"We're fine in here, although it's a little bit surreal," he added.
Nottinghamshire Police have warned residents to stay inside amid reports of an armed man holed up inside a snooker club in Hucknall town centre:
Residents unable to access homes advised to find alt temp accommodation or attend Hucknall Leisure Centre while incident continues #Hucknall
Officers are continuing to maintain cordon in #Hucknall. Armed officers at scene. Public are advised to remain indoors and avoid area.
Police have closed off a town centre in Nottinghamshire amid reports of an armed man holed up in a snooker hall.
Nottinghamshire Police said they were maintaining a cordon after responding to reports of "a man acting suspiciously" in the Spot On snooker club in Vine Terrace in Hucknall at about 2.40pm today.
People working in nearby businesses have been told to lock their doors and stay inside.
A pensioner is in a critical condition after being pulled from a river by a passer-by.
The man was airlifted to a hospital in Lincoln after being rescued from the River Trent near Newark Castle at about 5.30pm today.
Nottinghamshire Police are carrying out inquiries into the circumstances surrounding how the man came to be in the water and are appealing for witnesses to contact officers on 101.
Remains found in the garden of a house in a quiet cul-de-sac have the same distinctive feature that an elderly woman who used to live at the property had, police said.
The bodies of two people found buried in the garden are believed to be William Wycherley, who would now be 100, and his wife Patricia, 79.
The couple moved in to the semi-detached house in 2 Blenheim Close, Forest Town, Mansfield in 1987 but there has been no trace of them since 1998.
Patricia's maiden name was Moore it is believed she was born in Fulham, police said.