A car bomb attack outside a Londonderry court had nothing to do with Brexit, the Northern Ireland Secretary has said.
Karen Bradley said no one should try to draw a link with Saturday’s bombing, just a few miles from the border, with the UK’s impasse over its exit from the European Union and the debate over how to deal with the frontier between Northern Ireland and the Irish Republic.
Ms Bradley’s statement to the Commons came hours after detectives detained a fifth suspect over the dissident republican terror attack.
Meanwhile, there were also two significant security alerts in Derry on Monday following the hijacking of two vehicles by masked men.
"Nobody should try and draw any connection between what happened on Saturday night and any of the discussions we are having in this place or with our friends in Europe, the attack that happened on Saturday night is a result of a threat level that has been in place since before the Brexit vote," Ms Bradley said.
"These are plots and activities that these people have been working on and trying to carry out for many, many years and we need to be clear with them that those activities are not welcome, the people of Northern Ireland do not want to see this kind of activity on their streets."
A dissident republican grouping that styles itself as the New IRA has been blamed for the bombing, which caused no injuries, outside Bishop Street court.
Dramatic CCTV footage of the incident released by police showed a group of people walking past the car containing the bomb just minutes before the explosion.
The Brexit debate has prompted the Irish Government to warn of the prospect of an increase in violence if physical infrastructure is installed on the border - but the DUP has dismissed this as scaremongering.
Some believe the timing of Saturday's bombing may have had more to do with a symbolic anniversary in history of militant republicanism as it came ahead of the centenary of the outbreak of Ireland's War of Independence in 1919.
The 50-year-old man arrested on Monday was detained under the Terrorism Act.
Four men arrested on Sunday also remained in police custody on Monday evening.
