A suspected Irish Republican Army dissident already facing trial over one bomb was arraigned Tuesday on a charge of planting a car bomb outside a Northern Ireland courthouse.

Eamon Cassidy, 49, offered no plea and was ordered held without bail over his alleged role in planting a 100-pound (45-kilogram) car bomb across the street from the courthouse in Londonderry, Northern Ireland's second-largest city, in March 2011. Tuesday's arraignment took place in the same building.

Cassidy is already being held in Northern Ireland's main prison, Maghaberry, while awaiting trial over a small bomb that Londonderry police found in September 2011 when searching a car carrying Cassidy and other alleged IRA dissidents.

A prosecutor said Tuesday that police linked Cassidy to the attempted courthouse bombing by collecting his DNA following his September arrest and matching it to DNA traces found inside the car bearing the courthouse bomb.

British Army experts safely defused the device after an IRA splinter group made three telephoned warnings to a Londonderry taxi firm, a Catholic priest's home and another private residence near the bomb.

Londonderry is a power base for several small IRA factions opposed to the outlawed group's 2005 decisions to disarm and renounce violence. The predominantly Catholic city has suffered repeated disruption by the die-hards' bombings and hoax attacks over the past two years. Several blasts have caused cosmetic damage to hotels, banks, government buildings and tourism offices, but nobody has been seriously wounded.

The courthouse bomb was packed inside a beer keg and included a homemade detonator, a small core of commercial explosive, and a main explosive charge composed of fertilizer and sugar, prosecutors said.

After his September arrest, police testified that Cassidy and the other two men offered an innocent explanation for driving in a car with a bomb. They said Cassidy claimed that he had found the bomb lying in the middle of a road while out walking, picked it up, and asked his friends to help him deliver it to a priest's house for safekeeping.