Police last month spent four days searching Belfast's Antrim Road - dubbed "the Murder Mile" during the worst days of the Northern Ireland conflict - following telephoned warnings from an IRA faction that its members had hidden bombs in the area that failed to detonate.
Two days into the search, police found one small bomb inside a car. Two days later they found a second bomb taped to an abandoned preschool-sized bicycle. About 50 families were evacuated from their homes during the search operation.
Police said the three arrested men - aged 33, 34 and 38 - were being questioned at their major interrogation center in Antrim west of Belfast.
The senior investigator, Detective Chief Inspector Justyn Galloway, said the attackers apparently tried to lure police into the area by vandalizing the window of a shop, then telephoning the police to report the crime. But when police responded, neither bomb in the area detonated.
"A trap was put in place to kill police officers which could easily have murdered members of the public," Galloway said.
Countless civilians walked or drove past both undetonated devices before the IRA dissidents made more telephone calls warning vaguely of their presence somewhere in the area.
Several splinter groups opposed to the IRA's 1997 cease-fire have continued to mount occasional bomb and gun attacks in Northern Ireland, particularly since the 2007 formation of a Catholic-Protestant government that includes IRA veterans. The dissidents' goal is to destabilize the coalition and deter the Irish Catholic minority from cooperating with the police.
Dissident IRA gunmen killed two off-duty British soldiers and a policeman in two March 2009 attacks. But most dissident attacks since have fizzled because of police surveillance or the dissidents' own incompetence.
A majority of bombs fail to detonate. Those that do - including a half-dozen car bombs last year - have caused relatively little damage and no serious injuries. In August 2010, one booby-trap bomb designed to maim police instead hurt three children aged 2 to 12.
About 4,000 British troops remain based in Northern Ireland as part of its 1998 peace settlement, which reaffirmed Northern Ireland's status as a part of the United Kingdom. But the troops no longer have any role in combating IRA factions or other local paramilitary groups.