Northern Ireland terror threat level rated by MI5: Chris Heaton Harris says threat upgraded from substantial to severe - meaning an attack is highly likely

In a Written Ministerial Statement by the Secretary of State, Chris Heaton-Harris, he said the threat level to Northern Ireland is constantly monitored and is subject to a regular formal review.

"This is a systematic, comprehensive and rigorous process, based on the very latest intelligence and analysis of factors which drive the threat,” he said. "The threat level review takes into account a range of factors and analysis of recent incidents.”

The decision to change the threat level is taken by MI5, independently of Ministers, he added.

"MI5 has increased the threat to Northern Ireland from Northern Ireland Related Terrorism from ‘Substantial’ (an attack is likely) to ‘Severe’ (an attack is highly likely).”

The NIO advised that the public should remain vigilant, but not be alarmed, and continue to report any concerns they have to the PSNI.

"Over the last 25 years, Northern Ireland has transformed into a peaceful society. The Belfast (Good Friday) Agreement demonstrates how peaceful and democratic politics improve society,” Mr Heaton Harris said.

"However, a small number of people remain determined to cause harm to our communities through acts of politically motivated violence.

"In recent months, we have seen an increase in levels of activity relating to Northern Ireland Related Terrorism, which has targeted police officers serving their communities and also put at risk the lives of children and other members of the public.

"These attacks have no support, as demonstrated by the reaction to the abhorrent attempted murder of DCI Caldwell.

"I pay tribute to the tremendous efforts of the Police Service of Northern Ireland and security partners, and the determination and resilience of the Northern Ireland people, who are making Northern Ireland a safer place to live and work.

"The political future of Northern Ireland rests with the democratic will of the people and not the violent actions of the few. Together we will ensure there is no return to the violence of the past."

In a seperate statement, PSNI Chief Constable Simon Byrne also noted the threat level has been increased from substantial to severe by MI5.

"The independent assessment means the threat has moved from an attack is ‘likely’ to an attack is ‘highly likely’,” he added.

“This is part of an ongoing process of monitoring the threat level in Northern Ireland, which is conducted by MI5. We have spoken publicly about the number of attacks that have taken place in recent months, not least the attempted murder of DCI John Caldwell on February 22.

“We will relentlessly pursue those who seek to cause harm and terrorise our communities, and attack my officers and staff, and I pay tribute to them as they continue to deliver for our communities,” he said.

“I would also like to thank the community and political leaders of Northern Ireland for their overwhelming support for the Police Service in recent times. We will not be deterred from delivering a visible, accessible and responsive community focused policing service to keep people safe.”