Dissident republicans must end their campaign of violence, Sinn Fein's vice president Mary Lou McDonald has said.
She told crowds gathered for the annual 1916 Easter Rising commemoration at Milltown cemetery in west Belfast that militant splinter groups should stop immediately.
"Armed conflict is in the past; it has no place in the present; no-one has the right to inflict it on our children's future. The splinter groups who pursue armed actions today are acting out a travesty that too often has turned to tragedy. They should desist and desist immediately," she said.
Police have blamed dissidents for Saturday's bomb attack in Lurgan, Co Armagh.
Officers escaped injury after a small explosive device was placed inside a dog litter bin and detonated without warning while they investigated reports of an illegal parade.
Last week dissident grouping, Oglaigh na h'Eireann, said it left a bomb inside a van close to the venue for the G8 summit in Fermanagh.
Meanwhile, during a separate commemorative event in Dublin, Deputy First Minister Martin McGuinness warned that the peace established 15 years ago by the Good Friday Agreement 15 years ago could not be taken for granted.
"While much progress has been made, more needs to be done. Recent events on our streets have shown that.
"There are people who dream of wrecking the structures of change. They want to destroy rather than build. Their tools are bigotry, mistrust, militarism and sectarianism.
"Those who prefer conflict and confrontation must be opposed by political leaders united in a vision a peaceful, inclusive and shared future," he said.