BELFAST, Northern Ireland — On Tuesday morning, Aug. 10, a former police officer in his 50s left his house in County Tyrone climbed into his red Ford Mondeo and set out for the police station, where he worked as a security guard.

There was a bang as a bomb partially exploded under the car along Sweep Road. The man, badly shaken, walked away unscathed. If the explosive device had fully detonated he would be dead, according to district police commander Michael Skuce, who called his survival “unbelievable.”

The attempted murder was the third such attack in Northern Ireland in a week. The other two intended victims, a British army major in Bangor and a woman police officer in Kilkeel, both in County Down, escaped injury after devices fell off their automobiles without exploding.

Coming shortly after a 200-pound car bomb exploded outside a police station in Strand Road Derry, the attacks mark a concerted attempt by dissident anti-British republicans to reignite the war in Northern Ireland known as “The Troubles.” The bloody conflict killed 3,524 people, but wound down over a decade ago when the IRA gave up its armed campaign to unite Ireland and engaged instead in a successful peace process.

However, a small number of die-hard republicans, mainly based in disadvantaged nationalist housing projects, is showing a new intent and a new capability to conduct a sustained campaign. While the booby-trap bombs have failed to explode properly, the geographical spread of the attacks and the failure to detect the culprits indicate a level of organization and intelligence gathering that is causing widespread alarm.

Mid-Ulster Assembly member Ian McCrea, from the Democratic Unionist Party, suggested that it was time for the British army to be redeployed on the streets of Northern Ireland, an event that would undoubtedly play into the hands of the dissidents, given the traditional level of hostility to British soldiers in nationalist areas.

The upsurge in attacks comes after a hard-line faction of a dissident group called the Continuity IRA claimed to have overthrown its leadership of “tired, weary old men.”

“We intend to consolidate as a new guerrilla movement, we intend to recruit, to train and to equip for a long struggle,” an anonymous leader of the group said in an interview with Irish Times on July 26.

Continuity IRA members, who in 2009 shot dead a police constable, are believed to cooperate with another faction known as the Real IRA, which was responsible for the Omagh bombing in 1998 that killed 29 people, and which last year murdered two British soldiers in County Antrim. It accuses Sinn Fein of being absorbed into the “apparatus of British rule.”

Under a deal between the unionist and minority nationalist communities, backed by the governments in London and Dublin, Northern Ireland remained part of the United Kingdom but the nationalists were granted major concessions.

These included a power-sharing Assembly at Stormont, headed jointly by the leader of the Democratic Unionist Party, Peter Robinson and former IRA officer Martin McGuinness of Sinn Fein, which controls a civilianized police force called the Police Service of Northern Ireland.

There had been several recent symbolic events unthinkable a few years ago to mark the new era of peace — such as visits by former loyalist paramilitaries to the home in Dublin of the Irish president, Mary McAleese, and the nationalist game of hurling being played Aug. 7 in the grounds of Stormont, long a bastion of unionist power.

But in an echo of the turmoil of the early 1980s, when hunger strikes in prison encouraged nationalist support for the IRA, some 25 dissident republican prisoners are now engaged in a protest over conditions at Maghaberry prison.

However there is little nationalist sympathy for their cause now compared to then, and the British and Irish governments and the security forces on both sides of the Irish border are cooperating closely.

On Aug. 8, for example, police south of the border arrested five men in County Louth on charges of possessing firearms and belonging to an “illegal organization,” the euphemism used for a dissident republican group, planning attacks in Northern Ireland.

McGuinness has accused the hold-outs of treachery, arguing that the new constitutional arrangements in Ireland were approved democratically in a referendum on both sides of the border and that therefore there is no justification for a new war.

But public manifestations of nationalist anger during contentious loyalist parades are being used by dissidents to claim a level of support, and the reality of Northern Ireland today is that everyone connected with the police will be looking anxiously under their cars each morning for booby-trap bombs before going to work.

Editor's note: This story was updated to correct the dateline of Belfast, Northern Ireland.