The RUC special branch has issued a memo to all police commanders across Northern Ireland, warning them that IRA members opposed to the peace process could break the ceasefire.
The memo says: "It is possible that dissident elements of the Provisional IRA may not feel constrained by the current ceasefire. Local commanders should be aware of this situation and take it into consideration as part of the overall threat."
An RUC spokesman said last night night that "if there is a split in the Republican movement it would emphasise the need to maintain vigilance".