A bomb attack on a prison officer in Northern Ireland may be the first of a number of dissident republican murder bids launched to mark the centenary of the Easter Rising, police have warned.
Police commanders have expressed fears violent renegades are intent on killing security force members as a perverse way of commemorating the landmark republican anniversary.
The 52-year-old prison officer, a married father of three, required surgery after an explosive device detonated under the van he was driving to work in Belfast on Friday morning.
His condition has been described as stable. The long serving officer is based at Hydebank Wood Young Offenders Centre in south Belfast and works as a trainer for new recruits to the NI Prison Service.
Police Service of Northern Ireland (PSNI) Assistant Chief Constable Stephen Martin said he was extremely concerned about an upsurge in dissident activity ahead of the forthcoming 100th anniversary of the republican rebellion against British rule in Dublin.
Mr Martin said while the terror threat level in Northern Ireland has been categorised as "severe" for a number of years he was now describing it as "the upper end of severe".
"I believe there are people within dissident republican groupings who want to mark this centenary by killing police officers, prison officers and soldiers," he said.
"I am saying that publicly, I am saying it deliberately, and I am saying I need the help of the community. That is not inevitable, this does not need to happen, but we need the support of the community."
The 1916 uprising failed in its primary objective but it triggered a series of events that ultimately saw 26 counties of Ireland gain independence from Britain five years later.
Extremists who splintered from the mainstream republican movement during the peace process insist their armed actions will not end until the six counties of Northern Ireland are reunited with the Irish Republic.
The Rising has assumed great significance in wider republican and nationalist ideology and it will be marked by a series of state events in Dublin on March 27.
There are dozens of commemorative events planned north of the border as well. Mr Martin said his officers were "culturally sensitive" to those and would police them appropriately.
But he warned: "There are people within dissident republican groupings who want to mark the 2016 100th anniversary in an entirely more sinister way, who want to kill police officers, prison officers or soldiers.
"So we believe the threat is extremely high at the moment, it's at the upper end of severe, and we need community support and it's not inevitable that anyone needs to lose their life."
Stormont First Minister Arlene Foster and Deputy First Minister Martin McGuinness described the bombing as a "despicable and shocking" attack.
"Our thoughts and prayers are with this senior prison officer and his family as he is treated for his injuries in hospital," the ministers said.
"We join all right-thinking people in condemning these cowardly actions. As a prison officer, he is someone who serves and protects our community and we are united in our rejection of this attack."
The explosion happened in the Hillsborough Drive area off the Woodstock Road in the east of the city just after 7am.
The senior prison officer had just left home to drive to work.
Detectives are examining whether the bomb dislodged from the vehicle as it was going over a speed bump, thus lessening the impact of the blast.
The Woodstock Road is a predominantly unionist/loyalist area.
Mr Martin said: "The intention of this device was to kill, someone prepared this device, someone transported this device and someone planted this bomb."
The police commander added: "This could have been a fatality, the people who planned this wanted to kill a prison officer.
"This is a 52-year-old man, he has been in the prison service for 28 years, he's a married man, he has grown-up daughters, and we could be facing an absolutely tragic set of circumstances today in which a man who goes to work every day to keep people safe, to protect people, is actually deprived of his life in the most callous of circumstances."