A major security review has been ordered into a rooftop protest at Maghaberry Prison near Lisburn in Co Antrim on Saturday.
The eight prisoners who staged the protest were back in their cells last night.
The prison authorities managed to get the inmates down from the roof after intense negotiations.
The Northern Ireland Prison Service director general, Mr Peter Russell, has ordered a security review in an attempt to ensure that there is no repeat of the incident, which involved loyalists, republicans and other prisoners.
"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 the North's most notorious criminals and terrorists, began their protest on Saturday after they alleged cells in the jail were overcrowded.
But only half of those involved in the stand-off on top of Roe House wing actually shared cells, the prison service said.
All visits to the jail were suspended as jail managers studied the protesters' demands.
Among those held at the high-security complex is the notorious loyalist faction leader Johnny Adair and some of his most powerful enemies within the feuding Ulster Defence Association. - (PA)