THE targetting of prison officers by both republican and loyalist paramilitaries was fairly common at the height of the Troubles.

This intensified during the blanket protests and hunger strikes in the Maze in the late 1970s and early 1980s when staff were accused of using violence against prisoners.

In total 30 prison officers have been murdered since1970 with the last, David Black, shot dead as he travelled to work in Maghaberry in December 2012.

There are currently around 30 republican prisoners held in the separated wing of Maghaberry. They have been protesting since 2010 over restricted movement and forced strip searches among other issues.

However, the attempted murder of a 52-year-old prison officer in east Belfast will do little for the prisoners' cause given the now increased threat to prison staff which can only further sour relations between republicans and the NI Prison Service.

The man targeted had never worked on Maghaberry's separated landings. As a tutor in Hydebank Wood detention centre he would have had no contact with republican prisoners.

Nearing early retirement he was considered a 'soft target' in that he was unaware he was under any paramilitary threat and sources say was fairly lax with his personal security.

There is also a suggestion that police may have had some unspecific intelligence that there was to be an attack and had swamped parts of east and north Belfast on Thursday in a bid to thwart any attack.

However, it is unlikely that a tutor in Hydebank's workshops would have registered as a priority when assessing potential targets.

The homes of a number of high profile republicans were searched late on Thursday night with a heavy police presence including specialist anti terror officers on the ground in parts of the city.

The PSNI's helicopter was reported to have hovered over the republican Ardoyne area for most of the night.

Assistant Chief Constable Stephen Martin's warning following the bombing would suggest police are aware there is an increased threat level in the run up to Easter and the historic centenary of the Rising.

In recent years the PSNI has relied heavily on covert surveillance by MI5 and other intelligence agencies to monitor the activities of dissident republicans.

That intelligence in this case appears not to have been specific enough to prevent the attack on a prison officer in east Belfast.

And in the world of militant republicanism, it has often been said, they need to be lucky only once whereas the security services need to be lucky every time.