The terrorism threat level in Northern Ireland has been increased from substantial to severe, meaning an attack is highly likely.
In a written statement to MPs, the Northern Ireland secretary, Chris Heaton-Harris, said MI5 had increased the threat to Northern Ireland from Northern Ireland-related terrorism and the public should remain vigilant but not be alarmed.
The move by the Security Service comes a month after the senior police officer John Caldwell was shot by masked gunmen in Omagh, County Tyrone.
The detective chief inspector is understood to be in a “critical but stable condition” in hospital after he was shot while he packed footballs into his car alongside his son after a football training session. Thirteen arrests have been in connection with the attempted murder.
In his statement, Heaton-Harris said a “small number of people remain determined to cause harm to our communities through acts of politically motivated violence” as the terror threat level was raised.
“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,” he 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.”
Threat levels are designed to give a broad indication of the likelihood of a terrorist attack.
MI5 is responsible for setting the threat level from Northern Irish-related terrorism in Northern Ireland, while the threat level for the UK from international terrorism is set by the Joint Terrorism Analysis Centre.
The threat to the UK from terrorism is substantial, meaning an attack is likely.