Dissident republicans may exploit Brexit to carry out violent attacks, a senior police commander has said.

Police on both sides of the border have warned of a potential surge in dissident republican violence in Northern Ireland after Brexit.

Dissident republican activity has increased this year, with attempted bomb attacks on police in Belfast, Fermanagh and Armagh.

PSNI Detective Chief Superintendent Raymond Murray said while dissidents may exploit Brexit to carry out attacks, not all of them could be linked to Brexit.

He told UTV’s programme Up Close – Tied to Terror: “We have no information that would suggest that the attacks that have been carried out recently are directly linked to EU exit. We actually believe those attacks would have occurred without EU exit being on the agenda.

“No matter what way EU exit eventually works its way through the system, the dissident republicans will say ‘is there a means where we can exploit this?’, and that might lead to additional attacks.”

Detective Chief Superintendent Tony Howard, who is in charge of the Garda special detective unit in the Republic of Ireland, said there is “no doubt” there are people in the jurisdiction who “support these dissident republicans and their violent aims”, but they were in the minority.

“Certainly there are many individuals involved in dissident republicanism who are not young, they’ve been through many other campaigns, I wish they would go away but I cannot say that will ever happen fully.”

Detective Inspector Garda Patrick Marry, who retired last year after decades working in the border region, said he does not think there would be immediate action taken by dissident republicans on the day Britain leaves the EU.

“I don’t think they are going to if the UK leave Europe, there is going to be a big blast or anything of that nature, but over the coming weeks or months there will be an increase in violence – yes.”

The PSNI confirmed to the programme that out of the attacks in Northern Ireland in recent years, a “significant amount” have had some kind of assistance from dissidents in the Republic of Ireland.

Mr Marry said: “We’ve had knowledge of specific meetings with people from the north and south. There is no doubt there is co-operation amongst them.

“There are certain people who I would see as dedicated terrorists in that they have the mindset of using the bullet and bomb, and get the British out of Northern Ireland. These people aren’t going to change and that is the way they are.”

Supt Murray told the programme that dissident republicans have been “energised” by their murder of journalist Lyra McKee, enjoying the publicity the killing generated.

Ms McKee was shot dead during disturbances in Londonderry in April when rioters were attacking police.

“There were a very interesting set of circumstances we watched. We studied it very carefully after Lyra was murdered. For the first 48/72 hours the New IRA was in disarray and there was a degree of panic amongst them, that they had gone too far and the public backlash was going to damage them. After those three days their mindset changed. They almost felt they were victims,” said Supt Murray.

“The other thing then that manifested itself was an arrogance: ‘you can’t tell us what to do, nobody is going to tell us how to do it’, and unfortunately since Lyra McKee’s murder they have almost seemed to have derived a bit of energy, re-energising their campaign.”

Speaking six months on from Lyra’s death, her sister Nichola Corner said: “To know that these people haven’t learned anything from killing my sister, they haven’t learned a thing. It’s awful.

“They need to be stopped, everything that can be done should be done to stop them.  The people within their own communities should not be lending any support to that kind of insanity.”

UTV’s programme Up Close – Tied to Terror will be broadcast at 9pm on Tuesday October 22.