A man flees the scene of a hi-jacked truck set on fire in Belfast� AP

Fears that Dissident IRA groups are mounting a new offensive in Northern Ireland were being expressed after two serious incident this week.

A small dissident group, Oglaigh na HEireann (Irish volunteers) are believed to be behind the 600 pound bomb left in South Armagh near the border this week. The bomb was later defused by police.

The bomb was packed with homemade explosives and had a trip wire leading across the order to the Republic. It is believed the ONH were waiting for a police patrol to pass by before setting it off.

The ONH are made up of former provisional IRA members and some former INLA and Real IRA members. It is believed that some former IRA members who had not joined any other dissident group have recently come into their ranks.

Ironically, it was the appearance of another IRA splinter group, the Real IRA, when masked men showed up at a checkpoint in a nearby town that tipped police that dissident activity was going on.

They stepped up their state of alert and the ONH abandoned the bomb after police officers were not drawn into the area which is well known for dissident activity.

if the bomb had gone off it would have demolished several nearby houses. There has been widespread condemnation of the attempted bombings by local groups.

Meanwhile, in Derry the Real IRA claimed responsibility for trying to kill the parents of a Catholic policeman and also his sister when two devices were set off outside their separate homes.The Real IRA is targeting Catholic members of the new Northern police force. The Real IRA also carried out punishment shootings in a Nationalist neighborhood.