Commissioner Drew Harris has said that when bombs and mortars were discovered in Derry and Strabane three weeks ago Gardaí were quick to respond and offer support to the PSNI.
The former PSNI Deputy Chief Constable who has been Garda Commissioner for just over a year now said cross-border cooperation was routine for both forces.
He addressed the matter during a briefing of the Oireachtas Joint Committee on Justice and Equality.
Independent Louth T.D. Peter Fitzpatrick said: “Nobody wants to see the Troubles come back as a consequence of Brexit. We can all see what is happening in Derry. The border is more than 300 miles long.”
Mr Harris said: “The Deputy mentioned incidents in Derry. When such incidents happen, we are always quick to respond on this side of the border, in County Donegal, to make sure we support the PSNI. It would be the same across the border. People expect this of us.”
He said there had been considerable Brexit planning but that both he and his counterpart Simon Byrne, Chief Constable of the PSNI, have had to deal with an increase in attacks and activity by violent republicans.
“A lot of Brexit planning has happened. I entirely refute the suggestion that there is no Brexit plan. We have made, as best we can, provision for what Brexit may bring. We have had to deal with some of the things we feared would happen because there has been an increase in the number of attacks by groups such as the ‘New’ IRA in Northern Ireland. That has a consequence for us in terms of operations,” said the commissioner.
The Minister of Justice and Equality, Charles Flanagan, speaking in the Dáil, said he was aware of concerns in the border area given the “lethal terrorist intent” of some republican groups.
“Fortunately, we have never seen such a positive relationship between the PSNI and the Garda Síochána and I am confident that this close cooperation will enable both to continue to combat the threat posed by criminals who seek to exploit the policing challenges posed by the border.
“I am very much aware of the concerns that many communities close to the border have about recent criminal-related events and the impact of Brexit.
"There is no question about the lethal terrorist intent of paramilitary groups and the persistent threat they present, as well as the cross-border efforts of mobile organised crime groups responsible for multiple incidents, including burglary.”
The bomb discovered in a parked car during searches by police in Creggan recently.