Firefighters joined their colleagues from the police at HMP Ranby where a disturbance involving prisoners is ongoing.
Shortly after 7.30pm around 15 firefighters arrived outside the prison and began putting on their full kit before walking in through the main gate.
Officers carrying shields and other equipment were also seen going into the prison earlier.
The Labour MP whose Bassetlaw constituency includes HMP Ranby said his repeated warnings about "dysfunctional" management and serious staff shortages at the prison had been ignored by ministers and prison officials.
John Mann said: "It is a prison where, for quite a time, it's been clear prisoners have been running the prison."
He added that there were 80 fewer prison officers than previously - a 20% reduction - with many experienced individuals having been "forced out" over the past two years.
He said: "There are not the numbers or the expertise among the staff to deal with it. The governors were warned, the Government was warned, by me and by many others, that this would lead to disaster. He added: "I have raised this directly with the prisons minister more than once."
A fire was started at HMP Ranby during an ongoing disturbance which saw 120 inmates refused to return to their cells, The Prison Officers' Association (POA) said.
A spokesman for the Prison Service said minor damage was sustained and there were no injuries to staff or prisoners.
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.