Dissident republicans opposed to the peace process are the enemies of Ireland and are engaged in pointless violence, Martin McGuinness has said.
The Stormont deputy First Minister hit out at the murder of policemen and offered to meet and talk with violent groups to challenge their continuing attacks.
His comments came after it emerged Sinn Fein is in talks with members of the Protestant community and churches in Northern Ireland to begin a discussion on healing the wounds of decades of violence.
Mr McGuinness addressed delegates at his party's ard fheis in Co Kerry and told the annual conference of the impact of the dissident murder of Police Service of Northern Ireland (PSNI) officers Stephen Carroll and Ronan Kerr.
He referred to Pc Carroll's wife Kate, who last week saw two of her husband's killers jailed for the 2009 murder, and Ronan Kerr's mother Nuala who spoke out in favour of peace in the wake of her son's killing in 2011.
Mr McGuinness said: "Those involved in these violent acts don't believe for one minute that they further the cause of Irish reunification, what's more they also know the agreements we have negotiated are solid and secure."
He added: "Nuala Kerr and Kate Carroll, who I have met and respect, are good people who are genuine and sincere supporters of peace and change.
"My message to those who remain committed to violence is that it is not much of an achievement to think that the only thing you have shown the capability to break are two fine women's hearts.
"And other families and other mothers have suffered likewise."
He listed victims of dissident violence, including in his own city of Derry, and branded the attacks "shameful murders carried out by the enemies of the people of Derry and of Ireland".