A report compiled by HM Inspectors of Prisons reveals that data collected suggests violent incidents have doubled at the Category B prison over the past three years.
Inspectors found that incidents of self harm had significantly increased and an incident in 2016 led to the self-inflicted death of one prisoner. The data suggests that incidents are higher than would be the norm.
In May when the inspection was carried out, it was found that there were some 400 acts of violence reported during the previous six months, 25% of which were deemed to be of a serious nature.
This has resulted in a third of inmates feeling unsafe.
Sodexo, which runs the jail, said it would "continue to work tirelessly to improve safety".
"In common with many prisons, Forest Bank had seen increased levels of staff turnover in recent years", but all staff had the "maximum training, support and guidance possible to perform their job to a high standard".
HMP Forest Bank director Matt Spencer said the firm acknowledges
"There is more to do around levels of violence, but we are pleased this report recognises the positive steps we are taking to improve safety".
"We take on board the recommended improvements and will continue to work tirelessly to improve safety at HMP Forest Bank for all who live and work here,"
With a capacity of 1460 male prisoners the prison has experienced five deaths over the past 14 months with the latest death reported over the weekend on Sunday the 1st of September. Since the prison opened in 2016 it has seen 10 deaths in custody.
Inspectors reported that the relationships between inmates and staff were 'respectful and polite', however, there were concerns raised over the experience of some staff who it is said 'did not assert enough authority' whilst carrying out the role of supervising the prisoners. It was also suggested that because of this it presented a danger of some prisoner groups being able to take advantage.
Additionally there were concerns over low-level antisocial behaviour which was considered were not being fully addressed sufficiently, as well as concerns that 60% of inmates were sharing single occupancy cells.
The prison has responded by saying that they had already started to implement recommendations put forward by the Prisons and Probation Ombudsman, regarding the problems with prisoners self-harming.