An investigation by prison authorities in the North begins this morning after eight prisoners staged a rooftop protest at Maghaberry jail in Co Antrim yesterday.
Northern Ireland Prison Service director general Mr Peter Russell ordered a major security review in a bid to ensure there no repeat of the incident, which involved loyalists, republicans and non-terrorists.
"Clearly we will have to look at how the prisoners gained access to the roof and other aspects of the incident to see what lessons we can learn," Mr Russell said.
The inmates at Maghaberry, which houses some of Northern Ireland's most notorious criminals and terrorists, began their protest late last Friday night over what they claim is overcrowding at the prison.
But only half of those involved in the stand-off on top of Roe House wing actually share cells, the prison service said.
All visits to the jail were suspended as jail managers studied the protesters' demands.
After a day of intense negotiations yesterday the prsioner returned to their cells at around 5 p.m. Afterwards, a prison service spokesman insisted: "No concessions were made."
A hoax bomb alert added to the security headache yesterday, with 15 other inmates in the exercise yard cut off from the main building while British army explosives experts dealt with the fake device.
Mr Finlay Spratt, of the Prison Officers Association, had claimed that management was warned two weeks ago trouble was brewing over staff cuts and the large prison intake.
Among those held at the high-security complex are feared loyalist terror boss Johnny "Mad Dog" Adair - and some of his most powerful enemies within the feuding Ulster Defence Association.
Mr Spratt said: "We as prison officers, who have quite an experience of dealing with prisoners in the Northern Ireland Prison Service, have been continually saying to management that their policy of doubling these prisoners up was actually going to lead to what is happening."
Dissident republican terrorists kept in Maghaberry have previously warned their lives were under threat because they were held close to loyalists.
But after both sides joined the protest, a security source dismissed their claims, saying: "They say it's too dangerous being housed with loyalists, yet they got up on a roof with them.
"I can't think of a less safe place to be with your supposed sworn enemy."