There is a real risk that groups opposed to the Northern Ireland agreement will engage in terrorist acts to influence votes in the forthcoming referendum, according to the RUC Chief Constable, Mr Ronnie Flanagan.
They may also "seek to foment difficulties on the streets", he told RTE's Morning Ireland programme yesterday.
"It's a risk of which we are very aware and we'll be seeing that they have no opportunity to bring that risk to fruition," he said. Terrorist groups opposed to the agreement "pose a very real threat".
Asked about the feelings of police officers at the prospect of prisoners who had murdered colleagues getting early release, Mr Flanagan said: "Police officers are human beings and of course experience human feelings."
At the human level, "police officers might look on with some wonder at people guilty of very serious offences being released earlier than perhaps they should, but at the professional level the police officer is taught from day one of his or her training that it's their job to bring people into the criminal justice system. What happens thereafter is a matter for others in the criminal justice system.
"Of course people will be released only if they are so-called `qualifying prisoners', in other words, only if there is a true and lasting peace that can be trusted and if organisations of which they have been members are in a permanent, enduring cessation of any violent acts."
Asked about paramilitaries leaving their existing organisations and moving to organisations still committed to violence, he said such a drift was occurring.
"I think I would continue to describe it as a drift. It's certainly by no means like anything approaching a critical mass of any of the mainstream organisations. It is a drift that we're watching."