Watch: Four prisoners gain access to the roof at Maghaberry prison

A spokesperson for the service confirmed they got on to the roof in the Mourne complex but said the incident has been “brought under control”.

They said no prison staff or other inmates sustained any injuries and said the incident will be sent to the PSNI.

An NI Prison Service spokesperson said: “The Prison Service has confirmed that an incident at Maghaberry yesterday, during which four prisoners gained access to a roof in the Mourne complex within the prison, has ended.

"The situation was brought under control without injury to staff or prisoners. The rest of the prison was unaffected. The area will be assessed to ascertain how the prisoners were able to access the roof.

"The four prisoners will be charged under Prison Rules and their actions will be referred to the PSNI for investigation.”

Ulster Unionist Party leader Doug Beattie claimed staffing levels at the prison “had a part to play”.

"As with assaults on staff and prisoner on prisoner it is clear that staffing levels at HMP Maghaberry had a part to play in 4 prisoners getting onto the roof of a prison block.

"This cannot continue and it is important the Justice Minister conducts an urgent review and learning account to identify how this was able to happen.

"Without a Justice committee to scrutinise events in the prison it falls to the Minister to ensure the public are satisfied that all failings, be they procedural, structural or human, are addressed.”

In a statement, a Northern Ireland Fire and Rescue Service spokesperson said two appliances from Lisburn Fire Station attended the incident.

They added: “Firefighters were called to assist with an incident at Maghaberry Prison. No action was required from NIFRS and the incident was dealt with at 1.17am.”

The Department of Justice has been contacted.