The Garda Commissioner Noirin O'Sullivan says members of the force will be engaging in more exercises with the Defence Forces in preparation for a terror attack.

She has been responding to criticism that the gardaí are not prepared for a major incident here.

She has also confirmed that there will be 20 more officers in the Armed Response Unit by the end of the month.

Commissioner O'Sullivan has been outlining the steps they are taking in the wake of the recent attacks in the UK.

"We also have Operation Bilberry, which brings together a number of our own members from right around the country, to make sure that there's an understanding of what a response would be.

"That's going to increase even more - and what you are going to see is by the end of this month we will have more live exercises.

"That isn't because we have any specific intelligence, but I think that's the reality - that we have to have an agile response to be able to deal with instance as they occur, not matter what quarter they come from".

File photo of members of the Garda ERU (Emergency Response Unit) stand by a garda checkpoint in Dublin | Image: Rollingnews.ie

It comes as a security analyst warns Ireland would struggle to cope with any such terrorist attack.

Declan Power says any approach needs to be centralised in a new Government body.

"In the event of such an attack happening - which is a real possibility - we have a few distinct, natural elements in our favour being an island (and) having a small population.

"But if there was a mass casualty event we would struggle because of the number of first responders we would need, getting them into a location if it was in a city centre, like Dublin.

"We don't have any dedicated air frames for Air Ambulance; we do have Air Corps services (which) can provide that.

"They may have war games for this on paper or table-top exercises, but we've never seen a mass casualty exercise scenario in the city centre of Dublin or Cork like they have done in the UK."

He says: "We can only conclude that that would be a more difficult experience than some of our European neighbours - but I don't think there's any country in Europe that would be 100% well equipped to deal with a mass casualty scenario".

"The bottom line is we do have a lot of individual high quality expertise, operationally speaking, within the emergency services - within An Garda Síochána, the Defence Forces - but it's knitting that together, and that's where we don't see the efforts being put it".

Additional reporting: Jack Quann